Merge pull request #949 from python-babel/ruffify

Add ruff for linting

47 files changed, 785 insertions, 709 deletions

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b61dac4..4c3eb9c 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,4 +1,11 @@
 repos:
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.0.224
+    hooks:
+      - id: ruff
+        args:
+          - --fix
+          - --force-exclude
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.4.0
     hooks:
diff --git a/babel/core.py b/babel/core.py
index 5041c1b..ce564d7 100644
--- a/babel/core.py
+++ b/babel/core.py
@@ -46,6 +46,7 @@ if TYPE_CHECKING:
 _global_data = None
 _default_plural_rule = PluralRule({})
 
+
 def _raise_no_data_error():
     raise RuntimeError('The babel data files are not available. '
                        'This usually happens because you are using '
@@ -383,10 +384,12 @@ class Locale:
         for key in ('language', 'territory', 'script', 'variant'):
             if not hasattr(other, key):
                 return False
-        return (self.language == getattr(other, 'language')) and \
-            (self.territory == getattr(other, 'territory')) and \
-            (self.script == getattr(other, 'script')) and \
-            (self.variant == getattr(other, 'variant'))
+        return (
+            self.language == getattr(other, 'language') and  # noqa: B009
+            self.territory == getattr(other, 'territory') and  # noqa: B009
+            self.script == getattr(other, 'script') and  # noqa: B009
+            self.variant == getattr(other, 'variant')  # noqa: B009
+        )
 
     def __ne__(self, other: object) -> bool:
         return not self.__eq__(other)
diff --git a/babel/dates.py b/babel/dates.py
index 51bc7ff..e626df5 100644
--- a/babel/dates.py
+++ b/babel/dates.py
@@ -27,9 +27,9 @@ except ModuleNotFoundError:
     pytz = None
     import zoneinfo
 
+import datetime
 from bisect import bisect_right
 from collections.abc import Iterable
-import datetime
 
 from babel import localtime
 from babel.core import Locale, default_locale, get_global
@@ -49,7 +49,7 @@ if TYPE_CHECKING:
 #  empty set characters ( U+2205 )."
 #  - https://www.unicode.org/reports/tr35/tr35-dates.html#Metazone_Names
 
-NO_INHERITANCE_MARKER = u'\u2205\u2205\u2205'
+NO_INHERITANCE_MARKER = '\u2205\u2205\u2205'
 
 
 if pytz:
@@ -247,13 +247,13 @@ def get_timezone(zone: str | datetime.tzinfo | None = None) -> datetime.tzinfo:
     if pytz:
         try:
             return pytz.timezone(zone)
-        except pytz.UnknownTimeZoneError as exc:
+        except pytz.UnknownTimeZoneError as exc:  # noqa: F841
             pass
     else:
         assert zoneinfo
         try:
             return zoneinfo.ZoneInfo(zone)
-        except zoneinfo.ZoneInfoNotFoundError as exc:
+        except zoneinfo.ZoneInfoNotFoundError as exc:  # noqa: F841
             pass
 
     raise LookupError(f"Unknown timezone {zone}") from exc
@@ -558,11 +558,11 @@ def get_timezone_gmt(
     if return_z and hours == 0 and seconds == 0:
         return 'Z'
     elif seconds == 0 and width == 'iso8601_short':
-        return u'%+03d' % hours
+        return '%+03d' % hours
     elif width == 'short' or width == 'iso8601_short':
-        pattern = u'%+03d%02d'
+        pattern = '%+03d%02d'
     elif width == 'iso8601':
-        pattern = u'%+03d:%02d'
+        pattern = '%+03d:%02d'
     else:
         pattern = locale.zone_formats['gmt'] % '%+03d:%02d'
     return pattern % (hours, seconds // 60)
@@ -1083,10 +1083,10 @@ def format_timedelta(
                     break
             # This really should not happen
             if pattern is None:
-                return u''
+                return ''
             return pattern.replace('{0}', str(value))
 
-    return u''
+    return ''
 
 
 def _format_fallback_interval(
@@ -1349,8 +1349,7 @@ def parse_date(
         month_idx = format_str.index('l')
     day_idx = format_str.index('d')
 
-    indexes = [(year_idx, 'Y'), (month_idx, 'M'), (day_idx, 'D')]
-    indexes.sort()
+    indexes = sorted([(year_idx, 'Y'), (month_idx, 'M'), (day_idx, 'D')])
     indexes = {item[1]: idx for idx, item in enumerate(indexes)}
 
     # FIXME: this currently only supports numbers, but should also support month
@@ -1399,8 +1398,7 @@ def parse_time(
     min_idx = format_str.index('m')
     sec_idx = format_str.index('s')
 
-    indexes = [(hour_idx, 'H'), (min_idx, 'M'), (sec_idx, 'S')]
-    indexes.sort()
+    indexes = sorted([(hour_idx, 'H'), (min_idx, 'M'), (sec_idx, 'S')])
     indexes = {item[1]: idx for idx, item in enumerate(indexes)}
 
     # TODO: support time zones
@@ -1436,7 +1434,7 @@ class DateTimePattern:
         return pat
 
     def __mod__(self, other: DateTimeFormat) -> str:
-        if type(other) is not DateTimeFormat:
+        if not isinstance(other, DateTimeFormat):
             return NotImplemented
         return self.format % other
 
@@ -1829,7 +1827,7 @@ def parse_pattern(pattern: str) -> DateTimePattern:
 
     :param pattern: the formatting pattern to parse
     """
-    if type(pattern) is DateTimePattern:
+    if isinstance(pattern, DateTimePattern):
         return pattern
 
     if pattern in _pattern_cache:
@@ -1849,7 +1847,7 @@ def parse_pattern(pattern: str) -> DateTimePattern:
         else:
             raise NotImplementedError(f"Unknown token type: {tok_type}")
 
-    _pattern_cache[pattern] = pat = DateTimePattern(pattern, u''.join(result))
+    _pattern_cache[pattern] = pat = DateTimePattern(pattern, ''.join(result))
     return pat
 
 
@@ -1884,7 +1882,7 @@ def tokenize_pattern(pattern: str) -> list[tuple[str, str | tuple[str, int]]]:
         fieldchar[0] = ''
         fieldnum[0] = 0
 
-    for idx, char in enumerate(pattern.replace("''", '\0')):
+    for char in pattern.replace("''", '\0'):
         if quotebuf is None:
             if char == "'":  # quote started
                 if fieldchar[0]:
diff --git a/babel/localtime/__init__.py b/babel/localtime/__init__.py
index 9d227c7..1d65fb2 100644
--- a/babel/localtime/__init__.py
+++ b/babel/localtime/__init__.py
@@ -9,9 +9,9 @@
     :license: BSD, see LICENSE for more details.
 """
 
+import datetime
 import sys
 import time
-import datetime
 from threading import RLock
 
 if sys.platform == 'win32':
diff --git a/babel/localtime/_helpers.py b/babel/localtime/_helpers.py
index b7238f6..159f9a5 100644
--- a/babel/localtime/_helpers.py
+++ b/babel/localtime/_helpers.py
@@ -24,6 +24,7 @@ def _get_tzinfo(tzenv: str):
 
     return None
 
+
 def _get_tzinfo_or_raise(tzenv: str):
     tzinfo = _get_tzinfo(tzenv)
     if tzinfo is None:
diff --git a/babel/localtime/_unix.py b/babel/localtime/_unix.py
index 89b461a..eb81beb 100644
--- a/babel/localtime/_unix.py
+++ b/babel/localtime/_unix.py
@@ -1,14 +1,14 @@
+import datetime
 import os
 import re
 
-import datetime
-
 from babel.localtime._helpers import (
+    _get_tzinfo,
     _get_tzinfo_from_file,
     _get_tzinfo_or_raise,
-    _get_tzinfo,
 )
 
+
 def _tz_from_env(tzenv: str) -> datetime.tzinfo:
     if tzenv[0] == ':':
         tzenv = tzenv[1:]
diff --git a/babel/localtime/_win32.py b/babel/localtime/_win32.py
index 42f819a..1a52567 100644
--- a/babel/localtime/_win32.py
+++ b/babel/localtime/_win32.py
@@ -6,9 +6,10 @@ except ImportError:
     winreg = None
 
 import datetime
+from typing import Any, Dict, cast
+
 from babel.core import get_global
 from babel.localtime._helpers import _get_tzinfo_or_raise
-from typing import Any, Dict, cast
 
 # When building the cldr data on windows this module gets imported.
 # Because at that point there is no global.dat yet this call will
diff --git a/babel/messages/catalog.py b/babel/messages/catalog.py
index 4486bec..dead4aa 100644
--- a/babel/messages/catalog.py
+++ b/babel/messages/catalog.py
@@ -9,21 +9,20 @@
 """
 from __future__ import annotations
 
+import datetime
 import re
-
 from collections import OrderedDict
-from collections.abc import Generator, Iterable, Iterator
-import datetime
+from collections.abc import Iterable, Iterator
+from copy import copy
 from difflib import get_close_matches
 from email import message_from_string
-from copy import copy
 from typing import TYPE_CHECKING
 
 from babel import __version__ as VERSION
 from babel.core import Locale, UnknownLocaleError
 from babel.dates import format_datetime
 from babel.messages.plurals import get_plural
-from babel.util import distinct, LOCALTZ, FixedOffsetTimezone, _cmp
+from babel.util import LOCALTZ, FixedOffsetTimezone, _cmp, distinct
 
 if TYPE_CHECKING:
     from typing_extensions import TypeAlias
@@ -81,7 +80,7 @@ class Message:
     def __init__(
         self,
         id: _MessageID,
-        string: _MessageID | None = u'',
+        string: _MessageID | None = '',
         locations: Iterable[tuple[str, int]] = (),
         flags: Iterable[str] = (),
         auto_comments: Iterable[str] = (),
@@ -108,7 +107,7 @@ class Message:
         """
         self.id = id
         if not string and self.pluralizable:
-            string = (u'', u'')
+            string = ('', '')
         self.string = string
         self.locations = list(distinct(locations))
         self.flags = set(flags)
@@ -234,13 +233,14 @@ class TranslationError(Exception):
     translations are encountered."""
 
 
-DEFAULT_HEADER = u"""\
+DEFAULT_HEADER = """\
 # Translations template for PROJECT.
 # Copyright (C) YEAR ORGANIZATION
 # This file is distributed under the same license as the PROJECT project.
 # FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
 #"""
 
+
 def parse_separated_header(value: str) -> dict[str, str]:
     # Adapted from https://peps.python.org/pep-0594/#cgi
     from email.message import Message
@@ -445,7 +445,7 @@ class Catalog:
             value = self._force_text(value, encoding=self.charset)
             if name == 'project-id-version':
                 parts = value.split(' ')
-                self.project = u' '.join(parts[:-1])
+                self.project = ' '.join(parts[:-1])
                 self.version = parts[-1]
             elif name == 'report-msgid-bugs-to':
                 self.msgid_bugs_address = value
@@ -592,7 +592,7 @@ class Catalog:
         flags = set()
         if self.fuzzy:
             flags |= {'fuzzy'}
-        yield Message(u'', '\n'.join(buf), flags=flags)
+        yield Message('', '\n'.join(buf), flags=flags)
         for key in self._messages:
             yield self._messages[key]
 
@@ -737,7 +737,8 @@ class Catalog:
         if key in self._messages:
             del self._messages[key]
 
-    def update(self,
+    def update(
+        self,
         template: Catalog,
         no_fuzzy_matching: bool = False,
         update_header_comment: bool = False,
@@ -832,7 +833,7 @@ class Catalog:
                 if not isinstance(message.string, (list, tuple)):
                     fuzzy = True
                     message.string = tuple(
-                        [message.string] + ([u''] * (len(message.id) - 1))
+                        [message.string] + ([''] * (len(message.id) - 1))
                     )
                 elif len(message.string) != self.num_plurals:
                     fuzzy = True
@@ -842,7 +843,7 @@ class Catalog:
                 message.string = message.string[0]
             message.flags |= oldmsg.flags
             if fuzzy:
-                message.flags |= {u'fuzzy'}
+                message.flags |= {'fuzzy'}
             self[message.id] = message
 
         for message in template:
diff --git a/babel/messages/checkers.py b/babel/messages/checkers.py
index 00b84e5..38a26e8 100644
--- a/babel/messages/checkers.py
+++ b/babel/messages/checkers.py
@@ -13,8 +13,7 @@ from __future__ import annotations
 
 from collections.abc import Callable
 
-from babel.messages.catalog import Catalog, Message, TranslationError, PYTHON_FORMAT
-
+from babel.messages.catalog import PYTHON_FORMAT, Catalog, Message, TranslationError
 
 #: list of format chars that are compatible to each other
 _string_format_compatibilities = [
@@ -111,7 +110,7 @@ def _validate_format(format: str, alternative: str) -> None:
 
     def _check_positional(results: list[tuple[str, str]]) -> bool:
         positional = None
-        for name, char in results:
+        for name, _char in results:
             if positional is None:
                 positional = name is None
             else:
diff --git a/babel/messages/extract.py b/babel/messages/extract.py
index a426510..453742e 100644
--- a/babel/messages/extract.py
+++ b/babel/messages/extract.py
@@ -18,21 +18,29 @@
 from __future__ import annotations
 
 import ast
-from collections.abc import Callable, Collection, Generator, Iterable, Mapping, MutableSequence
 import io
 import os
 import sys
+from collections.abc import (
+    Callable,
+    Collection,
+    Generator,
+    Iterable,
+    Mapping,
+    MutableSequence,
+)
 from os.path import relpath
-from tokenize import generate_tokens, COMMENT, NAME, OP, STRING
-from typing import Any, TYPE_CHECKING
+from textwrap import dedent
+from tokenize import COMMENT, NAME, OP, STRING, generate_tokens
+from typing import TYPE_CHECKING, Any
 
 from babel.util import parse_encoding, parse_future_flags, pathmatch
-from textwrap import dedent
 
 if TYPE_CHECKING:
     from typing import IO, Protocol
-    from typing_extensions import Final, TypeAlias, TypedDict
+
     from _typeshed import SupportsItems, SupportsRead, SupportsReadline
+    from typing_extensions import Final, TypeAlias, TypedDict
 
     class _PyOptions(TypedDict, total=False):
         encoding: str
@@ -82,7 +90,6 @@ DEFAULT_KEYWORDS: dict[str, _Keyword] = {
 DEFAULT_MAPPING: list[tuple[str, str]] = [('**.py', 'python')]
 
 
-
 def _strip_comment_tags(comments: MutableSequence[str], tags: Iterable[str]):
     """Helper function for `extract` that strips comment tags from strings
     in a list of comment lines.  This functions operates in-place.
@@ -652,8 +659,7 @@ def extract_javascript(
             token = Token('operator', ')', token.lineno)
 
         if options.get('parse_template_string') and not funcname and token.type == 'template_string':
-            for item in parse_template_string(token.value, keywords, comment_tags, options, token.lineno):
-                yield item
+            yield from parse_template_string(token.value, keywords, comment_tags, options, token.lineno)
 
         elif token.type == 'operator' and token.value == '(':
             if funcname:
@@ -786,8 +792,7 @@ def parse_template_string(
                 if level == 0 and expression_contents:
                     expression_contents = expression_contents[0:-1]
                     fake_file_obj = io.BytesIO(expression_contents.encode())
-                    for item in extract_javascript(fake_file_obj, keywords, comment_tags, options, lineno):
-                        yield item
+                    yield from extract_javascript(fake_file_obj, keywords, comment_tags, options, lineno)
                     lineno += len(line_re.findall(expression_contents))
                     expression_contents = ''
         prev_character = character
diff --git a/babel/messages/frontend.py b/babel/messages/frontend.py
index c7e921d..ab094ec 100644
--- a/babel/messages/frontend.py
+++ b/babel/messages/frontend.py
@@ -8,6 +8,7 @@
     :license: BSD, see LICENSE for more details.
 """
 
+import datetime
 import fnmatch
 import logging
 import optparse
@@ -18,14 +19,19 @@ import sys
 import tempfile
 from collections import OrderedDict
 from configparser import RawConfigParser
-import datetime
 from io import StringIO
+from typing import Iterable
 
-from babel import __version__ as VERSION
 from babel import Locale, localedata
+from babel import __version__ as VERSION
 from babel.core import UnknownLocaleError
-from babel.messages.catalog import Catalog, DEFAULT_HEADER
-from babel.messages.extract import DEFAULT_KEYWORDS, DEFAULT_MAPPING, check_and_call_extract_file, extract_from_dir
+from babel.messages.catalog import DEFAULT_HEADER, Catalog
+from babel.messages.extract import (
+    DEFAULT_KEYWORDS,
+    DEFAULT_MAPPING,
+    check_and_call_extract_file,
+    extract_from_dir,
+)
 from babel.messages.mofile import write_mo
 from babel.messages.pofile import read_po, write_po
 from babel.util import LOCALTZ
@@ -38,15 +44,16 @@ try:
     distutils_log = log  # "distutils.log → (no replacement yet)"
 
     try:
-        from setuptools.errors import OptionError, SetupError, BaseError
+        from setuptools.errors import BaseError, OptionError, SetupError
     except ImportError:  # Error aliases only added in setuptools 59 (2021-11).
         OptionError = SetupError = BaseError = Exception
 
 except ImportError:
     from distutils import log as distutils_log
     from distutils.cmd import Command as _Command
-    from distutils.errors import DistutilsOptionError as OptionError, DistutilsSetupError as SetupError, DistutilsError as BaseError
-
+    from distutils.errors import DistutilsError as BaseError
+    from distutils.errors import DistutilsOptionError as OptionError
+    from distutils.errors import DistutilsSetupError as SetupError
 
 
 def listify_value(arg, split=None):
@@ -188,7 +195,7 @@ class compile_catalog(Command):
     def run(self):
         n_errors = 0
         for domain in self.domain:
-            for catalog, errors in self._run_domain(domain).items():
+            for errors in self._run_domain(domain).values():
                 n_errors += len(errors)
         if n_errors:
             self.log.error('%d errors encountered.', n_errors)
@@ -472,6 +479,27 @@ class extract_messages(Command):
         else:
             self.directory_filter = None
 
+    def _build_callback(self, path: str):
+        def callback(filename: str, method: str, options: dict):
+            if method == 'ignore':
+                return
+
+            # If we explicitly provide a full filepath, just use that.
+            # Otherwise, path will be the directory path and filename
+            # is the relative path from that dir to the file.
+            # So we can join those to get the full filepath.
+            if os.path.isfile(path):
+                filepath = path
+            else:
+                filepath = os.path.normpath(os.path.join(path, filename))
+
+            optstr = ''
+            if options:
+                opt_values = ", ".join(f'{k}="{v}"' for k, v in options.items())
+                optstr = f" ({opt_values})"
+            self.log.info('extracting messages from %s%s', filepath, optstr)
+        return callback
+
     def run(self):
         mappings = self._get_mappings()
         with open(self.output_file, 'wb') as outfile:
@@ -483,25 +511,7 @@ class extract_messages(Command):
                               header_comment=(self.header_comment or DEFAULT_HEADER))
 
             for path, method_map, options_map in mappings:
-                def callback(filename, method, options):
-                    if method == 'ignore':
-                        return
-
-                    # If we explicitly provide a full filepath, just use that.
-                    # Otherwise, path will be the directory path and filename
-                    # is the relative path from that dir to the file.
-                    # So we can join those to get the full filepath.
-                    if os.path.isfile(path):
-                        filepath = path
-                    else:
-                        filepath = os.path.normpath(os.path.join(path, filename))
-
-                    optstr = ''
-                    if options:
-                        opt_values = ", ".join(f'{k}="{v}"' for k, v in options.items())
-                        optstr = f" ({opt_values})"
-                    self.log.info('extracting messages from %s%s', filepath, optstr)
-
+                callback = self._build_callback(path)
                 if os.path.isfile(path):
                     current_dir = os.getcwd()
                     extracted = check_and_call_extract_file(
@@ -842,7 +852,7 @@ class update_catalog(Command):
                              omit_header=self.omit_header,
                              ignore_obsolete=self.ignore_obsolete,
                              include_previous=self.previous, width=self.width)
-            except:
+            except Exception:
                 os.remove(tmpname)
                 raise
 
@@ -937,7 +947,7 @@ class CommandLineInterface:
             identifiers = localedata.locale_identifiers()
             longest = max(len(identifier) for identifier in identifiers)
             identifiers.sort()
-            format = u'%%-%ds %%s' % (longest + 1)
+            format = '%%-%ds %%s' % (longest + 1)
             for identifier in identifiers:
                 locale = Locale.parse(identifier)
                 print(format % (identifier, locale.english_name))
@@ -1105,7 +1115,7 @@ def parse_mapping(fileobj, filename=None):
     return method_map, options_map
 
 
-def parse_keywords(strings=[]):
+def parse_keywords(strings: Iterable[str] = ()):
     """Parse keywords specifications from the given list of strings.
 
     >>> kw = sorted(parse_keywords(['_', 'dgettext:2', 'dngettext:2,3', 'pgettext:1c,2']).items())
diff --git a/babel/messages/jslexer.py b/babel/messages/jslexer.py
index 07fffde..0563f62 100644
--- a/babel/messages/jslexer.py
+++ b/babel/messages/jslexer.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """
     babel.messages.jslexer
     ~~~~~~~~~~~~~~~~~~~~~~
@@ -11,9 +10,8 @@
 """
 from __future__ import annotations
 
-from collections import namedtuple
-from collections.abc import Generator, Iterator, Sequence
 import re
+from collections.abc import Generator
 from typing import NamedTuple
 
 operators: list[str] = sorted([
@@ -34,11 +32,13 @@ line_join_re = re.compile(r'\\' + line_re.pattern)
 uni_escape_re = re.compile(r'[a-fA-F0-9]{1,4}')
 hex_escape_re = re.compile(r'[a-fA-F0-9]{1,2}')
 
+
 class Token(NamedTuple):
     type: str
     value: str
     lineno: int
 
+
 _rules: list[tuple[str | None, re.Pattern[str]]] = [
     (None, re.compile(r'\s+', re.UNICODE)),
     (None, re.compile(r'<!--.*')),
@@ -102,7 +102,7 @@ def unquote_string(string: str) -> str:
     add = result.append
     pos = 0
 
-    while 1:
+    while True:
         # scan for the next escape
         escape_pos = string.find('\\', pos)
         if escape_pos < 0:
@@ -155,7 +155,7 @@ def unquote_string(string: str) -> str:
     if pos < len(string):
         add(string[pos:])
 
-    return u''.join(result)
+    return ''.join(result)
 
 
 def tokenize(source: str, jsx: bool = True, dotted: bool = True, template_string: bool = True, lineno: int = 1) -> Generator[Token, None, None]:
@@ -174,7 +174,7 @@ def tokenize(source: str, jsx: bool = True, dotted: bool = True, template_string
 
     while pos < end:
         # handle regular rules first
-        for token_type, rule in rules:
+        for token_type, rule in rules:  # noqa: B007
             match = rule.match(source, pos)
             if match is not None:
                 break
diff --git a/babel/messages/mofile.py b/babel/messages/mofile.py
index a96f059..0a432a7 100644
--- a/babel/messages/mofile.py
+++ b/babel/messages/mofile.py
@@ -55,7 +55,7 @@ def read_mo(fileobj: SupportsRead[bytes]) -> Catalog:
 
     # Now put all messages from the .mo file buffer into the catalog
     # dictionary
-    for i in range(0, msgcount):
+    for _i in range(msgcount):
         mlen, moff = unpack(ii, buf[origidx:origidx + 8])
         mend = moff + mlen
         tlen, toff = unpack(ii, buf[transidx:transidx + 8])
diff --git a/babel/messages/plurals.py b/babel/messages/plurals.py
index 0fdf53b..eb8de47 100644
--- a/babel/messages/plurals.py
+++ b/babel/messages/plurals.py
@@ -9,9 +9,9 @@
 """
 from __future__ import annotations
 
-from babel.core import default_locale, Locale
 from operator import itemgetter
 
+from babel.core import Locale, default_locale
 
 # XXX: remove this file, duplication with babel.plural
 
diff --git a/babel/messages/pofile.py b/babel/messages/pofile.py
index b6d0d6e..aef8cbf 100644
--- a/babel/messages/pofile.py
+++ b/babel/messages/pofile.py
@@ -14,14 +14,15 @@ import os
 import re
 from collections.abc import Iterable
 from typing import TYPE_CHECKING
-from babel.core import Locale
 
+from babel.core import Locale
 from babel.messages.catalog import Catalog, Message
-from babel.util import wraptext, _cmp
+from babel.util import _cmp, wraptext
 
 if TYPE_CHECKING:
-    from _typeshed import SupportsWrite
     from typing import IO, AnyStr
+
+    from _typeshed import SupportsWrite
     from typing_extensions import Literal
 
 
@@ -133,7 +134,6 @@ class _NormalizedString:
         return self.__cmp__(other) != 0
 
 
-
 class PoFileParser:
     """Support class to  read messages from a ``gettext`` PO (portable object) file
     and add them to a `Catalog`
@@ -183,7 +183,7 @@ class PoFileParser:
             string = ['' for _ in range(self.catalog.num_plurals)]
             for idx, translation in self.translations:
                 if idx >= self.catalog.num_plurals:
-                    self._invalid_pofile(u"", self.offset, "msg has more translations than num_plurals of catalog")
+                    self._invalid_pofile("", self.offset, "msg has more translations than num_plurals of catalog")
                     continue
                 string[idx] = translation.denormalize()
             string = tuple(string)
@@ -319,8 +319,8 @@ class PoFileParser:
         # No actual messages found, but there was some info in comments, from which
         # we'll construct an empty header message
         if not self.counter and (self.flags or self.user_comments or self.auto_comments):
-            self.messages.append(_NormalizedString(u'""'))
-            self.translations.append([0, _NormalizedString(u'""')])
+            self.messages.append(_NormalizedString('""'))
+            self.translations.append([0, _NormalizedString('""')])
             self._add_message()
 
     def _invalid_pofile(self, line, lineno, msg) -> None:
@@ -451,17 +451,17 @@ def normalize(string: str, prefix: str = '', width: int = 76) -> str:
                     buf = []
                     size = 2
                     while chunks:
-                        l = len(escape(chunks[-1])) - 2 + prefixlen
-                        if size + l < width:
+                        length = len(escape(chunks[-1])) - 2 + prefixlen
+                        if size + length < width:
                             buf.append(chunks.pop())
-                            size += l
+                            size += length
                         else:
                             if not buf:
                                 # handle long chunks by putting them on a
                                 # separate line
                                 buf.append(chunks.pop())
                             break
-                    lines.append(u''.join(buf))
+                    lines.append(''.join(buf))
             else:
                 lines.append(line)
     else:
@@ -474,7 +474,7 @@ def normalize(string: str, prefix: str = '', width: int = 76) -> str:
     if lines and not lines[-1]:
         del lines[-1]
         lines[-1] += '\n'
-    return u'""\n' + u'\n'.join([(prefix + escape(line)) for line in lines])
+    return '""\n' + '\n'.join([(prefix + escape(line)) for line in lines])
 
 
 def write_po(
@@ -585,7 +585,7 @@ def write_po(
                 for line in comment_header.splitlines():
                     lines += wraptext(line, width=width,
                                       subsequent_indent='# ')
-                comment_header = u'\n'.join(lines)
+                comment_header = '\n'.join(lines)
             _write(f"{comment_header}\n")
 
         for comment in message.user_comments:
@@ -614,11 +614,13 @@ def write_po(
                     locs.append(location)
             _write_comment(' '.join(locs), prefix=':')
         if message.flags:
-            _write('#%s\n' % ', '.join([''] + sorted(message.flags)))
+            _write(f"#{', '.join(['', *sorted(message.flags)])}\n")
 
         if message.previous_id and include_previous:
-            _write_comment('msgid %s' % _normalize(message.previous_id[0]),
-                           prefix='|')
+            _write_comment(
+                f'msgid {_normalize(message.previous_id[0])}',
+                prefix='|',
+            )
             if len(message.previous_id) > 1:
                 _write_comment('msgid_plural %s' % _normalize(
                     message.previous_id[1]
diff --git a/babel/numbers.py b/babel/numbers.py
index 5a05f91..399b70b 100644
--- a/babel/numbers.py
+++ b/babel/numbers.py
@@ -19,11 +19,11 @@
 #  - https://www.unicode.org/reports/tr35/ (Appendix G.6)
 from __future__ import annotations
 
+import datetime
 import decimal
 import re
-from typing import TYPE_CHECKING, Any, overload
 import warnings
-import datetime
+from typing import TYPE_CHECKING, Any, overload
 
 from babel.core import Locale, default_locale, get_global
 from babel.localedata import LocaleDataDict
@@ -324,7 +324,7 @@ def get_decimal_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
 
     :param locale: the `Locale` object or locale identifier
     """
-    return Locale.parse(locale).number_symbols.get('decimal', u'.')
+    return Locale.parse(locale).number_symbols.get('decimal', '.')
 
 
 def get_plus_sign_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
@@ -335,7 +335,7 @@ def get_plus_sign_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
 
     :param locale: the `Locale` object or locale identifier
     """
-    return Locale.parse(locale).number_symbols.get('plusSign', u'+')
+    return Locale.parse(locale).number_symbols.get('plusSign', '+')
 
 
 def get_minus_sign_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
@@ -346,7 +346,7 @@ def get_minus_sign_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
 
     :param locale: the `Locale` object or locale identifier
     """
-    return Locale.parse(locale).number_symbols.get('minusSign', u'-')
+    return Locale.parse(locale).number_symbols.get('minusSign', '-')
 
 
 def get_exponential_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
@@ -357,7 +357,7 @@ def get_exponential_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
 
     :param locale: the `Locale` object or locale identifier
     """
-    return Locale.parse(locale).number_symbols.get('exponential', u'E')
+    return Locale.parse(locale).number_symbols.get('exponential', 'E')
 
 
 def get_group_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
@@ -368,11 +368,11 @@ def get_group_symbol(locale: Locale | str | None = LC_NUMERIC) -> str:
 
     :param locale: the `Locale` object or locale identifier
     """
-    return Locale.parse(locale).number_symbols.get('group', u',')
+    return Locale.parse(locale).number_symbols.get('group', ',')
 
 
 def format_number(number: float | decimal.Decimal | str, locale: Locale | str | None = LC_NUMERIC) -> str:
-    u"""Return the given number formatted for a specific locale.
+    """Return the given number formatted for a specific locale.
 
     >>> format_number(1099, locale='en_US')  # doctest: +SKIP
     u'1,099'
@@ -418,7 +418,7 @@ def format_decimal(
     decimal_quantization: bool = True,
     group_separator: bool = True,
 ) -> str:
-    u"""Return the given decimal number formatted for a specific locale.
+    """Return the given decimal number formatted for a specific locale.
 
     >>> format_decimal(1.2345, locale='en_US')
     u'1.234'
@@ -473,7 +473,7 @@ def format_compact_decimal(
     locale: Locale | str | None = LC_NUMERIC,
     fraction_digits: int = 0,
 ) -> str:
-    u"""Return the given decimal number formatted for a specific locale in compact form.
+    """Return the given decimal number formatted for a specific locale in compact form.
 
     >>> format_compact_decimal(12345, format_type="short", locale='en_US')
     u'12K'
@@ -555,7 +555,7 @@ def format_currency(
     decimal_quantization: bool = True,
     group_separator: bool = True,
 ) -> str:
-    u"""Return formatted currency value.
+    """Return formatted currency value.
 
     >>> format_currency(1099.98, 'USD', locale='en_US')
     u'$1,099.98'
@@ -653,7 +653,7 @@ def format_currency(
         try:
             pattern = locale.currency_formats[format_type]
         except KeyError:
-            raise UnknownCurrencyFormatError(f"{format_type!r} is not a known currency format type")
+            raise UnknownCurrencyFormatError(f"{format_type!r} is not a known currency format type") from None
 
     return pattern.apply(
         number, locale, currency=currency, currency_digits=currency_digits,
@@ -711,7 +711,7 @@ def format_compact_currency(
     locale: Locale | str | None = LC_NUMERIC,
     fraction_digits: int = 0
 ) -> str:
-    u"""Format a number as a currency value in compact form.
+    """Format a number as a currency value in compact form.
 
     >>> format_compact_currency(12345, 'USD', locale='en_US')
     u'$12K'
@@ -870,8 +870,8 @@ def parse_number(string: str, locale: Locale | str | None = LC_NUMERIC) -> int:
     """
     try:
         return int(string.replace(get_group_symbol(locale), ''))
-    except ValueError:
-        raise NumberFormatError(f"{string!r} is not a valid number")
+    except ValueError as ve:
+        raise NumberFormatError(f"{string!r} is not a valid number") from ve
 
 
 def parse_decimal(string: str, locale: Locale | str | None = LC_NUMERIC, strict: bool = False) -> decimal.Decimal:
@@ -916,7 +916,7 @@ def parse_decimal(string: str, locale: Locale | str | None = LC_NUMERIC, strict:
     decimal_symbol = get_decimal_symbol(locale)
 
     if not strict and (
-        group_symbol == u'\xa0' and  # if the grouping symbol is U+00A0 NO-BREAK SPACE,
+        group_symbol == '\xa0' and  # if the grouping symbol is U+00A0 NO-BREAK SPACE,
         group_symbol not in string and  # and the string to be parsed does not contain it,
         ' ' in string  # but it does contain a space instead,
     ):
@@ -926,20 +926,20 @@ def parse_decimal(string: str, locale: Locale | str | None = LC_NUMERIC, strict:
     try:
         parsed = decimal.Decimal(string.replace(group_symbol, '')
                                        .replace(decimal_symbol, '.'))
-    except decimal.InvalidOperation:
-        raise NumberFormatError(f"{string!r} is not a valid decimal number")
+    except decimal.InvalidOperation as exc:
+        raise NumberFormatError(f"{string!r} is not a valid decimal number") from exc
     if strict and group_symbol in string:
         proper = format_decimal(parsed, locale=locale, decimal_quantization=False)
         if string != proper and string.rstrip('0') != (proper + decimal_symbol):
             try:
                 parsed_alt = decimal.Decimal(string.replace(decimal_symbol, '')
                                                    .replace(group_symbol, '.'))
-            except decimal.InvalidOperation:
+            except decimal.InvalidOperation as exc:
                 raise NumberFormatError(
                     f"{string!r} is not a properly formatted decimal number. "
                     f"Did you mean {proper!r}?",
                     suggestions=[proper],
-                )
+                ) from exc
             else:
                 proper_alt = format_decimal(parsed_alt, locale=locale, decimal_quantization=False)
                 if proper_alt == proper:
@@ -1095,7 +1095,7 @@ class NumberPattern:
         scale = 0
         if '%' in ''.join(self.prefix + self.suffix):
             scale = 2
-        elif u'‰' in ''.join(self.prefix + self.suffix):
+        elif '‰' in ''.join(self.prefix + self.suffix):
             scale = 3
         return scale
 
@@ -1222,11 +1222,11 @@ class NumberPattern:
             number if self.number_pattern != '' else '',
             self.suffix[is_negative]])
 
-        if u'¤' in retval:
-            retval = retval.replace(u'¤¤¤',
+        if '¤' in retval:
+            retval = retval.replace('¤¤¤',
                                     get_currency_name(currency, value, locale))
-            retval = retval.replace(u'¤¤', currency.upper())
-            retval = retval.replace(u'¤', get_currency_symbol(currency, locale))
+            retval = retval.replace('¤¤', currency.upper())
+            retval = retval.replace('¤', get_currency_symbol(currency, locale))
 
         # remove single quotes around text, except for doubled single quotes
         # which are replaced with a single quote
diff --git a/babel/plural.py b/babel/plural.py
index b4f54c0..26073ff 100644
--- a/babel/plural.py
+++ b/babel/plural.py
@@ -115,7 +115,7 @@ class PluralRule:
             rules = rules.items()
         found = set()
         self.abstract: list[tuple[str, Any]] = []
-        for key, expr in sorted(list(rules)):
+        for key, expr in sorted(rules):
             if key not in _plural_tags:
                 raise ValueError(f"unknown tag {key!r}")
             elif key in found:
@@ -325,6 +325,7 @@ def cldr_modulo(a: float, b: float) -> float:
 class RuleError(Exception):
     """Raised if a rule is malformed."""
 
+
 _VARS = {
     'n',  # absolute value of the source number.
     'i',  # integer digits of n.
@@ -363,6 +364,7 @@ def tokenize_rule(s: str) -> list[tuple[str, str]]:
                             'Got unexpected %r' % s[pos])
     return result[::-1]
 
+
 def test_next_token(
     tokens: list[tuple[str, str]],
     type_: str,
@@ -519,7 +521,7 @@ class _Parser:
 
 def _binary_compiler(tmpl):
     """Compiler factory for the `_Compiler`."""
-    return lambda self, l, r: tmpl % (self.compile(l), self.compile(r))
+    return lambda self, left, right: tmpl % (self.compile(left), self.compile(right))
 
 
 def _unary_compiler(tmpl):
@@ -627,7 +629,7 @@ class _UnicodeCompiler(_Compiler):
     compile_mod = _binary_compiler('%s mod %s')
 
     def compile_not(self, relation):
-        return self.compile_relation(negated=True, *relation[1])
+        return self.compile_relation(*relation[1], negated=True)
 
     def compile_relation(self, method, expr, range_list, negated=False):
         ranges = []
diff --git a/babel/support.py b/babel/support.py
index a8dd230..242b492 100644
--- a/babel/support.py
+++ b/babel/support.py
@@ -16,23 +16,26 @@ import decimal
 import gettext
 import locale
 import os
-import datetime
 from collections.abc import Iterator
 from typing import TYPE_CHECKING, Any, Callable
 
 from babel.core import Locale
-
-from babel.dates import (format_date, format_datetime, format_time,
-                         format_timedelta, get_timezone)
-from babel.numbers import (format_compact_currency, format_compact_decimal,
-                           format_currency, format_decimal, format_percent,
-                           format_scientific)
+from babel.dates import format_date, format_datetime, format_time, format_timedelta
+from babel.numbers import (
+    format_compact_currency,
+    format_compact_decimal,
+    format_currency,
+    format_decimal,
+    format_percent,
+    format_scientific,
+)
 
 if TYPE_CHECKING:
     from typing_extensions import Literal
 
     from babel.dates import _PredefinedTimeFormat
 
+
 class Format:
     """Wrapper class providing the various date and number formatting functions
     bound to a specific locale and time-zone.
@@ -77,6 +80,7 @@ class Format:
         """Return a date and time formatted according to the given pattern.
 
         >>> from datetime import datetime
+        >>> from babel.dates import get_timezone
         >>> fmt = Format('en_US', tzinfo=get_timezone('US/Eastern'))
         >>> fmt.datetime(datetime(2007, 4, 1, 15, 30))
         u'Apr 1, 2007, 11:30:00 AM'
@@ -91,6 +95,7 @@ class Format:
         """Return a time formatted according to the given pattern.
 
         >>> from datetime import datetime
+        >>> from babel.dates import get_timezone
         >>> fmt = Format('en_US', tzinfo=get_timezone('US/Eastern'))
         >>> fmt.time(datetime(2007, 4, 1, 15, 30))
         u'11:30:00 AM'
@@ -333,7 +338,7 @@ class LazyProxy:
         return LazyProxy(
             self._func,
             enable_cache=self._is_cache_enabled,
-            *self._args,
+            *self._args,  # noqa: B026
             **self._kwargs
         )
 
@@ -342,7 +347,7 @@ class LazyProxy:
         return LazyProxy(
             deepcopy(self._func, memo),
             enable_cache=deepcopy(self._is_cache_enabled, memo),
-            *deepcopy(self._args, memo),
+            *deepcopy(self._args, memo),  # noqa: B026
             **deepcopy(self._kwargs, memo)
         )
 
diff --git a/babel/units.py b/babel/units.py
index 1180bd1..0c72ee9 100644
--- a/babel/units.py
+++ b/babel/units.py
@@ -9,6 +9,7 @@ from babel.numbers import LC_NUMERIC, format_decimal
 if TYPE_CHECKING:
     from typing_extensions import Literal
 
+
 class UnknownUnitError(ValueError):
     def __init__(self, unit: str, locale: Locale) -> None:
         ValueError.__init__(self, f"{unit} is not a known unit in {locale}")
diff --git a/babel/util.py b/babel/util.py
index d25ec53..a5403e6 100644
--- a/babel/util.py
+++ b/babel/util.py
@@ -11,19 +11,20 @@ from __future__ import annotations
 
 import codecs
 import collections
+import datetime
 import os
 import re
 import textwrap
-from babel import localtime, dates
-
 from collections.abc import Generator, Iterable
-import datetime
 from typing import IO, Any, TypeVar
 
+from babel import dates, localtime
+
 missing = object()
 
 _T = TypeVar("_T")
 
+
 def distinct(iterable: Iterable[_T]) -> Generator[_T, None, None]:
     """Yield all items in an iterable collection that are distinct.
 
@@ -43,6 +44,7 @@ def distinct(iterable: Iterable[_T]) -> Generator[_T, None, None]:
             yield item
             seen.add(item)
 
+
 # Regexp to match python magic encoding line
 PYTHON_MAGIC_COMMENT_re = re.compile(
     br'[ \t\f]* \# .* coding[=:][ \t]*([-\w.]+)', re.VERBOSE)
diff --git a/docs/conf.py b/docs/conf.py
index c0e2389..5118f72 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -10,7 +10,8 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys, os
+import os
+import sys
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -42,8 +43,8 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'Babel'
-copyright = u'2022, The Babel Team'
+project = 'Babel'
+copyright = '2022, The Babel Team'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -193,8 +194,8 @@ latex_elements = {
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-  ('index', 'Babel.tex', u'Babel Documentation',
-   u'The Babel Team', 'manual'),
+  ('index', 'Babel.tex', 'Babel Documentation',
+   'The Babel Team', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -223,7 +224,7 @@ latex_logo = '_static/logo.png'
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    ('index', 'babel', u'Babel Documentation', [u'The Babel Team'], 1),
+    ('index', 'babel', 'Babel Documentation', ['The Babel Team'], 1),
 ]
 
 # If true, show URL addresses after external links.
@@ -236,8 +237,8 @@ man_pages = [
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-  ('index_', 'Babel', u'Babel Documentation',
-   u'The Babel Team', 'Babel', 'One line description of project.',
+  ('index_', 'Babel', 'Babel Documentation',
+   'The Babel Team', 'Babel', 'One line description of project.',
    'Miscellaneous'),
 ]
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..dbd137c
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,23 @@
+[tool.ruff]
+target-version = "py37"
+select = [
+    "B",
+    "C",
+    "E",
+    "F",
+    "I",
+    "SIM300",
+    "UP",
+]
+ignore = [
+    "C901",  # Complexity
+    "E501",  # Line length
+    "E731",  # Do not assign a lambda expression (we use them on purpose)
+    "E741",  # Ambiguous variable name
+    "UP012",  # "utf-8" is on purpose
+]
+extend-exclude = [
+    "tests/messages/data",
+]
+[tool.ruff.per-file-ignores]
+"scripts/import_cldr.py" = ["E402"]
diff --git a/scripts/download_import_cldr.py b/scripts/download_import_cldr.py
index 57995b5..ab455ac 100755
--- a/scripts/download_import_cldr.py
+++ b/scripts/download_import_cldr.py
@@ -1,15 +1,14 @@
 #!/usr/bin/env python3
 
 import contextlib
+import hashlib
 import os
-import sys
 import shutil
-import hashlib
-import zipfile
 import subprocess
+import sys
+import zipfile
 from urllib.request import urlretrieve
 
-
 URL = 'http://unicode.org/Public/cldr/41/cldr-common-41.0.zip'
 FILENAME = 'cldr-common-41.0.zip'
 # Via https://unicode.org/Public/cldr/41/hashes/SHASUM512
@@ -38,7 +37,7 @@ def is_good_file(filename):
         return False
     h = hashlib.sha512()
     with open(filename, 'rb') as f:
-        while 1:
+        while True:
             blk = f.read(BLKSIZE)
             if not blk:
                 break
diff --git a/scripts/dump_data.py b/scripts/dump_data.py
index e419050..041a410 100755
--- a/scripts/dump_data.py
+++ b/scripts/dump_data.py
@@ -14,7 +14,7 @@
 from optparse import OptionParser
 from pprint import pprint
 
-from babel.localedata import load, LocaleDataDict
+from babel.localedata import LocaleDataDict, load
 
 
 def main():
diff --git a/scripts/dump_global.py b/scripts/dump_global.py
index 6696415..3fc95b6 100755
--- a/scripts/dump_global.py
+++ b/scripts/dump_global.py
@@ -11,10 +11,11 @@
 # individuals. For the exact contribution history, see the revision
 # history and logs, available at http://babel.edgewall.org/log/.
 
-import cPickle as pickle
 import os
-from pprint import pprint
 import sys
+from pprint import pprint
+
+import cPickle as pickle
 
 import babel
 
diff --git a/scripts/generate_authors.py b/scripts/generate_authors.py
index e2e3add..64c0af8 100644
--- a/scripts/generate_authors.py
+++ b/scripts/generate_authors.py
@@ -1,8 +1,7 @@
+import os
 from collections import Counter
 from subprocess import check_output
 
-import os
-
 root_path = os.path.realpath(os.path.join(os.path.dirname(__file__), '..'))
 
 
diff --git a/scripts/import_cldr.py b/scripts/import_cldr.py
index 5de707c..5630ba8 100755
--- a/scripts/import_cldr.py
+++ b/scripts/import_cldr.py
@@ -12,13 +12,12 @@
 # history and logs, available at http://babel.edgewall.org/log/.
 
 import collections
-from optparse import OptionParser
+import logging
 import os
 import pickle
 import re
 import sys
-import logging
-
+from optparse import OptionParser
 from xml.etree import ElementTree
 
 # Make sure we're using Babel source, and not some previously installed version
@@ -44,7 +43,7 @@ def _text(elem):
     for child in elem:
         buf.append(_text(child))
     buf.append(elem.tail or '')
-    return u''.join(filter(None, buf)).strip()
+    return ''.join(filter(None, buf)).strip()
 
 
 NAME_RE = re.compile(r"^\w+$")
@@ -130,7 +129,7 @@ def _time_to_seconds_past_midnight(time_expr):
         return None
     if time_expr.count(":") == 1:
         time_expr += ":00"
-    hour, minute, second = [int(p, 10) for p in time_expr.split(":")]
+    hour, minute, second = (int(p, 10) for p in time_expr.split(":"))
     return hour * 60 * 60 + minute * 60 + second
 
 
@@ -991,6 +990,5 @@ def parse_measurement_systems(data, tree):
             _import_type_text(measurement_systems, measurement_system, type=type)
 
 
-
 if __name__ == '__main__':
     main()
diff --git a/setup.py b/setup.py
index db63216..df6ad8b 100755
--- a/setup.py
+++ b/setup.py
@@ -1,7 +1,7 @@
 import subprocess
 import sys
 
-from setuptools import setup, Command
+from setuptools import Command, setup
 
 try:
     from babel import __version__
diff --git a/tests/conftest.py b/tests/conftest.py
index 0506a83..67e3ce9 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,4 +1,5 @@
 import os
+
 import pytest
 
 try:
diff --git a/tests/messages/test_catalog.py b/tests/messages/test_catalog.py
index e9b15a8..273c83f 100644
--- a/tests/messages/test_catalog.py
+++ b/tests/messages/test_catalog.py
@@ -15,7 +15,7 @@ import datetime
 import unittest
 from io import StringIO
 
-from babel.dates import format_datetime, UTC
+from babel.dates import UTC, format_datetime
 from babel.messages import catalog, pofile
 from babel.util import FixedOffsetTimezone
 
@@ -89,34 +89,34 @@ class CatalogTestCase(unittest.TestCase):
 
     def test_update_message_changed_to_plural(self):
         cat = catalog.Catalog()
-        cat.add(u'foo', u'Voh')
+        cat.add('foo', 'Voh')
         tmpl = catalog.Catalog()
-        tmpl.add((u'foo', u'foos'))
+        tmpl.add(('foo', 'foos'))
         cat.update(tmpl)
         assert cat['foo'].string == ('Voh', '')
         assert cat['foo'].fuzzy
 
     def test_update_message_changed_to_simple(self):
         cat = catalog.Catalog()
-        cat.add(u'foo' u'foos', (u'Voh', u'Vöhs'))
+        cat.add('foo' 'foos', ('Voh', 'Vöhs'))
         tmpl = catalog.Catalog()
-        tmpl.add(u'foo')
+        tmpl.add('foo')
         cat.update(tmpl)
         assert cat['foo'].string == 'Voh'
         assert cat['foo'].fuzzy
 
     def test_update_message_updates_comments(self):
         cat = catalog.Catalog()
-        cat[u'foo'] = catalog.Message('foo', locations=[('main.py', 5)])
+        cat['foo'] = catalog.Message('foo', locations=[('main.py', 5)])
         assert cat['foo'].auto_comments == []
         assert cat['foo'].user_comments == []
         # Update cat[u'foo'] with a new location and a comment
-        cat[u'foo'] = catalog.Message('foo', locations=[('main.py', 7)],
-                                      user_comments=['Foo Bar comment 1'])
+        cat['foo'] = catalog.Message('foo', locations=[('main.py', 7)],
+                                     user_comments=['Foo Bar comment 1'])
         assert cat['foo'].user_comments == ['Foo Bar comment 1']
         # now add yet another location with another comment
-        cat[u'foo'] = catalog.Message('foo', locations=[('main.py', 9)],
-                                      auto_comments=['Foo Bar comment 2'])
+        cat['foo'] = catalog.Message('foo', locations=[('main.py', 9)],
+                                     auto_comments=['Foo Bar comment 2'])
         assert cat['foo'].auto_comments == ['Foo Bar comment 2']
 
     def test_update_fuzzy_matching_with_case_change(self):
@@ -404,21 +404,21 @@ def test_catalog_plural_forms():
 
 def test_catalog_setitem():
     cat = catalog.Catalog()
-    cat[u'foo'] = catalog.Message(u'foo')
-    assert cat[u'foo'].id == 'foo'
+    cat['foo'] = catalog.Message('foo')
+    assert cat['foo'].id == 'foo'
 
     cat = catalog.Catalog()
-    cat[u'foo'] = catalog.Message(u'foo', locations=[('main.py', 1)])
-    assert cat[u'foo'].locations == [('main.py', 1)]
-    cat[u'foo'] = catalog.Message(u'foo', locations=[('utils.py', 5)])
-    assert cat[u'foo'].locations == [('main.py', 1), ('utils.py', 5)]
+    cat['foo'] = catalog.Message('foo', locations=[('main.py', 1)])
+    assert cat['foo'].locations == [('main.py', 1)]
+    cat['foo'] = catalog.Message('foo', locations=[('utils.py', 5)])
+    assert cat['foo'].locations == [('main.py', 1), ('utils.py', 5)]
 
 
 def test_catalog_add():
     cat = catalog.Catalog()
-    foo = cat.add(u'foo')
+    foo = cat.add('foo')
     assert foo.id == 'foo'
-    assert cat[u'foo'] is foo
+    assert cat['foo'] is foo
 
 
 def test_catalog_update():
@@ -427,9 +427,9 @@ def test_catalog_update():
     template.add('blue', locations=[('main.py', 100)])
     template.add(('salad', 'salads'), locations=[('util.py', 42)])
     cat = catalog.Catalog(locale='de_DE')
-    cat.add('blue', u'blau', locations=[('main.py', 98)])
-    cat.add('head', u'Kopf', locations=[('util.py', 33)])
-    cat.add(('salad', 'salads'), (u'Salat', u'Salate'),
+    cat.add('blue', 'blau', locations=[('main.py', 98)])
+    cat.add('head', 'Kopf', locations=[('util.py', 33)])
+    cat.add(('salad', 'salads'), ('Salat', 'Salate'),
             locations=[('util.py', 38)])
 
     cat.update(template)
@@ -440,11 +440,11 @@ def test_catalog_update():
     assert msg1.locations == [('main.py', 99)]
 
     msg2 = cat['blue']
-    assert msg2.string == u'blau'
+    assert msg2.string == 'blau'
     assert msg2.locations == [('main.py', 100)]
 
     msg3 = cat['salad']
-    assert msg3.string == (u'Salat', u'Salate')
+    assert msg3.string == ('Salat', 'Salate')
     assert msg3.locations == [('util.py', 42)]
 
     assert 'head' not in cat
diff --git a/tests/messages/test_extract.py b/tests/messages/test_extract.py
index 3873191..7a0df8e 100644
--- a/tests/messages/test_extract.py
+++ b/tests/messages/test_extract.py
@@ -41,14 +41,14 @@ msg10 = dngettext(getDomain(), 'Page', 'Pages', 3)
         assert messages == [
             (1, '_', None, []),
             (2, 'ungettext', (None, None, None), []),
-            (3, 'ungettext', (u'Babel', None, None), []),
-            (4, 'ungettext', (None, u'Babels', None), []),
-            (5, 'ungettext', (u'bunny', u'bunnies', None), []),
-            (6, 'ungettext', (None, u'bunnies', None), []),
+            (3, 'ungettext', ('Babel', None, None), []),
+            (4, 'ungettext', (None, 'Babels', None), []),
+            (5, 'ungettext', ('bunny', 'bunnies', None), []),
+            (6, 'ungettext', (None, 'bunnies', None), []),
             (7, '_', None, []),
-            (8, 'gettext', u'Rabbit', []),
-            (9, 'dgettext', (u'wiki', None), []),
-            (10, 'dngettext', (None, u'Page', u'Pages', None), []),
+            (8, 'gettext', 'Rabbit', []),
+            (9, 'dgettext', ('wiki', None), []),
+            (10, 'dngettext', (None, 'Page', 'Pages', None), []),
         ]
 
     def test_extract_default_encoding_ascii(self):
@@ -60,7 +60,7 @@ msg10 = dngettext(getDomain(), 'Page', 'Pages', 3)
         assert messages == [(1, '_', 'a', [])]
 
     def test_extract_default_encoding_utf8(self):
-        buf = BytesIO(u'_("☃")'.encode('UTF-8'))
+        buf = BytesIO('_("☃")'.encode('UTF-8'))
         messages = list(extract.extract_python(
             buf, list(extract.DEFAULT_KEYWORDS), [], {},
         ))
@@ -351,7 +351,7 @@ msg = _('Bonjour à tous')
         assert messages[0][3] == ['NOTE: hello']
 
     def test_utf8_message_with_magic_comment(self):
-        buf = BytesIO(u"""# -*- coding: utf-8 -*-
+        buf = BytesIO("""# -*- coding: utf-8 -*-
 # NOTE: hello
 msg = _('Bonjour à tous')
 """.encode('utf-8'))
@@ -360,7 +360,7 @@ msg = _('Bonjour à tous')
         assert messages[0][3] == ['NOTE: hello']
 
     def test_utf8_message_with_utf8_bom(self):
-        buf = BytesIO(codecs.BOM_UTF8 + u"""
+        buf = BytesIO(codecs.BOM_UTF8 + """
 # NOTE: hello
 msg = _('Bonjour à tous')
 """.encode('utf-8'))
@@ -369,7 +369,7 @@ msg = _('Bonjour à tous')
         assert messages[0][3] == ['NOTE: hello']
 
     def test_utf8_message_with_utf8_bom_and_magic_comment(self):
-        buf = BytesIO(codecs.BOM_UTF8 + u"""# -*- coding: utf-8 -*-
+        buf = BytesIO(codecs.BOM_UTF8 + """# -*- coding: utf-8 -*-
 # NOTE: hello
 msg = _('Bonjour à tous')
 """.encode('utf-8'))
@@ -378,7 +378,7 @@ msg = _('Bonjour à tous')
         assert messages[0][3] == ['NOTE: hello']
 
     def test_utf8_bom_with_latin_magic_comment_fails(self):
-        buf = BytesIO(codecs.BOM_UTF8 + u"""# -*- coding: latin-1 -*-
+        buf = BytesIO(codecs.BOM_UTF8 + """# -*- coding: latin-1 -*-
 # NOTE: hello
 msg = _('Bonjour à tous')
 """.encode('utf-8'))
@@ -386,7 +386,7 @@ msg = _('Bonjour à tous')
             list(extract.extract_python(buf, ('_',), ['NOTE:'], {}))
 
     def test_utf8_raw_strings_match_unicode_strings(self):
-        buf = BytesIO(codecs.BOM_UTF8 + u"""
+        buf = BytesIO(codecs.BOM_UTF8 + """
 msg = _('Bonjour à tous')
 msgu = _(u'Bonjour à tous')
 """.encode('utf-8'))
@@ -527,7 +527,7 @@ nbsp = _('\xa0')
 """)
         messages = list(extract.extract('python', buf,
                                         extract.DEFAULT_KEYWORDS, [], {}))
-        assert messages[0][1] == u'\xa0'
+        assert messages[0][1] == '\xa0'
 
     def test_f_strings(self):
         buf = BytesIO(br"""
@@ -542,10 +542,10 @@ t4 = _(f'spameggs {t1}')  # should not be extracted
 """)
         messages = list(extract.extract('python', buf, extract.DEFAULT_KEYWORDS, [], {}))
         assert len(messages) == 4
-        assert messages[0][1] == u'foobar'
-        assert messages[1][1] == u'spameggsfeast'
-        assert messages[2][1] == u'spameggskerroshampurilainen'
-        assert messages[3][1] == u'whoa! a flying shark... hello'
+        assert messages[0][1] == 'foobar'
+        assert messages[1][1] == 'spameggsfeast'
+        assert messages[2][1] == 'spameggskerroshampurilainen'
+        assert messages[3][1] == 'whoa! a flying shark... hello'
 
     def test_f_strings_non_utf8(self):
         buf = BytesIO(b"""
@@ -554,4 +554,4 @@ t2 = _(f'\xe5\xe4\xf6' f'\xc5\xc4\xd6')
 """)
         messages = list(extract.extract('python', buf, extract.DEFAULT_KEYWORDS, [], {}))
         assert len(messages) == 1
-        assert messages[0][1] == u'åäöÅÄÖ'
+        assert messages[0][1] == 'åäöÅÄÖ'
diff --git a/tests/messages/test_frontend.py b/tests/messages/test_frontend.py
index e91d02b..e540e71 100644
--- a/tests/messages/test_frontend.py
+++ b/tests/messages/test_frontend.py
@@ -9,26 +9,38 @@
 # This software consists of voluntary contributions made by many
 # individuals. For the exact contribution history, see the revision
 # history and logs, available at http://babel.edgewall.org/log/.
-import shlex
-from datetime import datetime
-from freezegun import freeze_time
-from io import StringIO
-from setuptools import Distribution
 import logging
 import os
+import shlex
 import shutil
 import sys
 import time
 import unittest
+from datetime import datetime
+from io import StringIO
 
 import pytest
+from freezegun import freeze_time
+from setuptools import Distribution
 
 from babel import __version__ as VERSION
 from babel.dates import format_datetime
-from babel.messages import frontend, Catalog
-from babel.messages.frontend import CommandLineInterface, extract_messages, update_catalog, OptionError, BaseError
-from babel.util import LOCALTZ
+from babel.messages import Catalog, frontend
+from babel.messages.frontend import (
+    BaseError,
+    CommandLineInterface,
+    OptionError,
+    extract_messages,
+    update_catalog,
+)
 from babel.messages.pofile import read_po, write_po
+from babel.util import LOCALTZ
+
+TEST_PROJECT_DISTRIBUTION_DATA = {
+    "name": "TestProject",
+    "version": "0.1",
+    "packages": ["project"],
+}
 
 this_dir = os.path.abspath(os.path.dirname(__file__))
 data_dir = os.path.join(this_dir, 'data')
@@ -47,11 +59,7 @@ class CompileCatalogTestCase(unittest.TestCase):
         self.olddir = os.getcwd()
         os.chdir(data_dir)
 
-        self.dist = Distribution(dict(
-            name='TestProject',
-            version='0.1',
-            packages=['project']
-        ))
+        self.dist = Distribution(TEST_PROJECT_DISTRIBUTION_DATA)
         self.cmd = frontend.compile_catalog(self.dist)
         self.cmd.initialize_options()
 
@@ -77,11 +85,7 @@ class ExtractMessagesTestCase(unittest.TestCase):
         self.olddir = os.getcwd()
         os.chdir(data_dir)
 
-        self.dist = Distribution(dict(
-            name='TestProject',
-            version='0.1',
-            packages=['project']
-        ))
+        self.dist = Distribution(TEST_PROJECT_DISTRIBUTION_DATA)
         self.cmd = frontend.extract_messages(self.dist)
         self.cmd.initialize_options()
 
@@ -350,11 +354,7 @@ class InitCatalogTestCase(unittest.TestCase):
         self.olddir = os.getcwd()
         os.chdir(data_dir)
 
-        self.dist = Distribution(dict(
-            name='TestProject',
-            version='0.1',
-            packages=['project']
-        ))
+        self.dist = Distribution(TEST_PROJECT_DISTRIBUTION_DATA)
         self.cmd = frontend.init_catalog(self.dist)
         self.cmd.initialize_options()
 
diff --git a/tests/messages/test_js_extract.py b/tests/messages/test_js_extract.py
index 95985c0..82f5379 100644
--- a/tests/messages/test_js_extract.py
+++ b/tests/messages/test_js_extract.py
@@ -1,5 +1,7 @@
 from io import BytesIO
+
 import pytest
+
 from babel.messages import extract
 
 
@@ -35,32 +37,32 @@ msg10 = dngettext(domain, 'Page', 'Pages', 3)
         list(extract.extract('javascript', buf, extract.DEFAULT_KEYWORDS, [],
                              {}))
     assert messages == [
-        (5, (u'bunny', u'bunnies'), [], None),
-        (8, u'Rabbit', [], None),
-        (10, (u'Page', u'Pages'), [], None)
+        (5, ('bunny', 'bunnies'), [], None),
+        (8, 'Rabbit', [], None),
+        (10, ('Page', 'Pages'), [], None)
     ]
 
 
 def test_message_with_line_comment():
-    buf = BytesIO(u"""\
+    buf = BytesIO("""\
 // NOTE: hello
 msg = _('Bonjour à tous')
 """.encode('utf-8'))
     messages = list(extract.extract_javascript(buf, ('_',), ['NOTE:'], {}))
-    assert messages[0][2] == u'Bonjour à tous'
-    assert messages[0][3] == [u'NOTE: hello']
+    assert messages[0][2] == 'Bonjour à tous'
+    assert messages[0][3] == ['NOTE: hello']
 
 
 def test_message_with_multiline_comment():
-    buf = BytesIO(u"""\
+    buf = BytesIO("""\
 /* NOTE: hello
 and bonjour
   and servus */
 msg = _('Bonjour à tous')
 """.encode('utf-8'))
     messages = list(extract.extract_javascript(buf, ('_',), ['NOTE:'], {}))
-    assert messages[0][2] == u'Bonjour à tous'
-    assert messages[0][3] == [u'NOTE: hello', 'and bonjour', '  and servus']
+    assert messages[0][2] == 'Bonjour à tous'
+    assert messages[0][3] == ['NOTE: hello', 'and bonjour', '  and servus']
 
 
 def test_ignore_function_definitions():
@@ -91,11 +93,11 @@ bar()
 _('no comment here')
 """)
     messages = list(extract.extract_javascript(buf, ('_',), ['NOTE:'], {}))
-    assert messages[0][2] == u'Something'
-    assert messages[0][3] == [u'NOTE: this will']
-    assert messages[1][2] == u'Something else'
-    assert messages[1][3] == [u'NOTE: this will show up', 'too.']
-    assert messages[2][2] == u'no comment here'
+    assert messages[0][2] == 'Something'
+    assert messages[0][3] == ['NOTE: this will']
+    assert messages[1][2] == 'Something else'
+    assert messages[1][3] == ['NOTE: this will show up', 'too.']
+    assert messages[2][2] == 'no comment here'
     assert messages[2][3] == []
 
 
diff --git a/tests/messages/test_jslexer.py b/tests/messages/test_jslexer.py
index bd6322e..3889f0b 100644
--- a/tests/messages/test_jslexer.py
+++ b/tests/messages/test_jslexer.py
@@ -3,9 +3,9 @@ from babel.messages import jslexer
 
 def test_unquote():
     assert jslexer.unquote_string('""') == ''
-    assert jslexer.unquote_string(r'"h\u00ebllo"') == u"hëllo"
-    assert jslexer.unquote_string(r'"h\xebllo"') == u"hëllo"
-    assert jslexer.unquote_string(r'"\xebb"') == u"ëb"
+    assert jslexer.unquote_string(r'"h\u00ebllo"') == "hëllo"
+    assert jslexer.unquote_string(r'"h\xebllo"') == "hëllo"
+    assert jslexer.unquote_string(r'"\xebb"') == "ëb"
 
 
 def test_dollar_in_identifier():
diff --git a/tests/messages/test_mofile.py b/tests/messages/test_mofile.py
index 6e026a8..6a702ed 100644
--- a/tests/messages/test_mofile.py
+++ b/tests/messages/test_mofile.py
@@ -14,7 +14,7 @@ import os
 import unittest
 from io import BytesIO
 
-from babel.messages import mofile, Catalog
+from babel.messages import Catalog, mofile
 from babel.support import Translations
 
 
@@ -42,12 +42,12 @@ class WriteMoTestCase(unittest.TestCase):
         # can be applied to all subsequent messages by GNUTranslations
         # (ensuring all messages are safely converted to unicode)
         catalog = Catalog(locale='en_US')
-        catalog.add(u'', '''\
+        catalog.add('', '''\
 "Content-Type: text/plain; charset=utf-8\n"
 "Content-Transfer-Encoding: 8bit\n''')
-        catalog.add(u'foo', 'Voh')
-        catalog.add((u'There is', u'There are'), (u'Es gibt', u'Es gibt'))
-        catalog.add(u'Fizz', '')
+        catalog.add('foo', 'Voh')
+        catalog.add(('There is', 'There are'), ('Es gibt', 'Es gibt'))
+        catalog.add('Fizz', '')
         catalog.add(('Fuzz', 'Fuzzes'), ('', ''))
         buf = BytesIO()
         mofile.write_mo(buf, catalog)
@@ -67,18 +67,18 @@ class WriteMoTestCase(unittest.TestCase):
 
     def test_empty_translation_with_fallback(self):
         catalog1 = Catalog(locale='fr_FR')
-        catalog1.add(u'', '''\
+        catalog1.add('', '''\
 "Content-Type: text/plain; charset=utf-8\n"
 "Content-Transfer-Encoding: 8bit\n''')
-        catalog1.add(u'Fuzz', '')
+        catalog1.add('Fuzz', '')
         buf1 = BytesIO()
         mofile.write_mo(buf1, catalog1)
         buf1.seek(0)
         catalog2 = Catalog(locale='fr')
-        catalog2.add(u'', '''\
+        catalog2.add('', '''\
 "Content-Type: text/plain; charset=utf-8\n"
 "Content-Transfer-Encoding: 8bit\n''')
-        catalog2.add(u'Fuzz', 'Flou')
+        catalog2.add('Fuzz', 'Flou')
         buf2 = BytesIO()
         mofile.write_mo(buf2, catalog2)
         buf2.seek(0)
diff --git a/tests/messages/test_pofile.py b/tests/messages/test_pofile.py
index a72368b..f668ea0 100644
--- a/tests/messages/test_pofile.py
+++ b/tests/messages/test_pofile.py
@@ -10,16 +10,18 @@
 # individuals. For the exact contribution history, see the revision
 # history and logs, available at http://babel.edgewall.org/log/.
 
-from datetime import datetime
 import unittest
+from datetime import datetime
 from io import BytesIO, StringIO
+
 import pytest
 
 from babel.core import Locale
-from babel.messages.catalog import Catalog, Message
 from babel.messages import pofile
+from babel.messages.catalog import Catalog, Message
 from babel.util import FixedOffsetTimezone
 
+
 class ReadPoTestCase(unittest.TestCase):
 
     def test_preserve_locale(self):
@@ -49,7 +51,7 @@ msgstr "Voh"''')
         assert catalog.domain == 'mydomain'
 
     def test_applies_specified_encoding_during_read(self):
-        buf = BytesIO(u'''
+        buf = BytesIO('''
 msgid ""
 msgstr ""
 "Project-Id-Version:  3.15\\n"
@@ -204,7 +206,7 @@ msgstr "Bahr"
 ''')
         catalog = pofile.read_po(buf)
         assert len(catalog.obsolete) == 1
-        message = catalog.obsolete[u'foofoo']
+        message = catalog.obsolete['foofoo']
         assert message.id == 'foofoo'
         assert message.string == 'VohVooooh'
         assert message.user_comments == ['This is an obsolete message']
@@ -225,7 +227,7 @@ msgstr "Bahr"
 ''')
         catalog = pofile.read_po(buf)
         assert len(catalog) == 1
-        message = catalog[u'bar']
+        message = catalog['bar']
         assert message.id == 'bar'
         assert message.string == 'Bahr'
         assert message.user_comments == ['This message is not obsolete']
@@ -247,7 +249,7 @@ msgstr "Bahr"
 ''')
         catalog = pofile.read_po(buf)
         assert len(catalog) == 1
-        message = catalog[u'bar']
+        message = catalog['bar']
         assert message.id == 'bar'
         assert message.string == 'Bahr'
         assert message.user_comments == ['This message is not obsolete']
@@ -296,7 +298,7 @@ msgstr "Bahr"
         catalog = pofile.read_po(buf)
         assert len(catalog) == 2
         assert len(catalog.obsolete) == 1
-        message = catalog.obsolete[u"foo"]
+        message = catalog.obsolete["foo"]
         assert message.context == 'other'
         assert message.string == 'Voh'
 
@@ -484,7 +486,7 @@ msgstr[2] "Vohs [text]"
     def test_invalid_pofile_with_abort_flag(self):
         parser = pofile.PoFileParser(None, abort_invalid=True)
         lineno = 10
-        line = u'Algo esta mal'
+        line = 'Algo esta mal'
         msg = 'invalid file'
         with pytest.raises(pofile.PoFileError):
             parser._invalid_pofile(line, lineno, msg)
@@ -494,8 +496,8 @@ class WritePoTestCase(unittest.TestCase):
 
     def test_join_locations(self):
         catalog = Catalog()
-        catalog.add(u'foo', locations=[('main.py', 1)])
-        catalog.add(u'foo', locations=[('utils.py', 3)])
+        catalog.add('foo', locations=[('main.py', 1)])
+        catalog.add('foo', locations=[('utils.py', 3)])
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=True)
         assert buf.getvalue().strip() == b'''#: main.py:1 utils.py:3
@@ -504,17 +506,17 @@ msgstr ""'''
 
     def test_write_po_file_with_specified_charset(self):
         catalog = Catalog(charset='iso-8859-1')
-        catalog.add('foo', u'äöü', locations=[('main.py', 1)])
+        catalog.add('foo', 'äöü', locations=[('main.py', 1)])
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=False)
         po_file = buf.getvalue().strip()
         assert b'"Content-Type: text/plain; charset=iso-8859-1\\n"' in po_file
-        assert u'msgstr "äöü"'.encode('iso-8859-1') in po_file
+        assert 'msgstr "äöü"'.encode('iso-8859-1') in po_file
 
     def test_duplicate_comments(self):
         catalog = Catalog()
-        catalog.add(u'foo', auto_comments=['A comment'])
-        catalog.add(u'foo', auto_comments=['A comment'])
+        catalog.add('foo', auto_comments=['A comment'])
+        catalog.add('foo', auto_comments=['A comment'])
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=True)
         assert buf.getvalue().strip() == b'''#. A comment
@@ -577,10 +579,10 @@ msgstr ""'''
 
     def test_wrap_locations_with_hyphens(self):
         catalog = Catalog()
-        catalog.add(u'foo', locations=[
+        catalog.add('foo', locations=[
             ('doupy/templates/base/navmenu.inc.html.py', 60)
         ])
-        catalog.add(u'foo', locations=[
+        catalog.add('foo', locations=[
             ('doupy/templates/job-offers/helpers.html', 22)
         ])
         buf = BytesIO()
@@ -623,9 +625,9 @@ msgstr ""
 
     def test_pot_with_translator_comments(self):
         catalog = Catalog()
-        catalog.add(u'foo', locations=[('main.py', 1)],
+        catalog.add('foo', locations=[('main.py', 1)],
                     auto_comments=['Comment About `foo`'])
-        catalog.add(u'bar', locations=[('utils.py', 3)],
+        catalog.add('bar', locations=[('utils.py', 3)],
                     user_comments=['Comment About `bar` with',
                                    'multiple lines.'])
         buf = BytesIO()
@@ -643,8 +645,8 @@ msgstr ""'''
 
     def test_po_with_obsolete_message(self):
         catalog = Catalog()
-        catalog.add(u'foo', u'Voh', locations=[('main.py', 1)])
-        catalog.obsolete['bar'] = Message(u'bar', u'Bahr',
+        catalog.add('foo', 'Voh', locations=[('main.py', 1)])
+        catalog.obsolete['bar'] = Message('bar', 'Bahr',
                                           locations=[('utils.py', 3)],
                                           user_comments=['User comment'])
         buf = BytesIO()
@@ -659,7 +661,7 @@ msgstr "Voh"
 
     def test_po_with_multiline_obsolete_message(self):
         catalog = Catalog()
-        catalog.add(u'foo', u'Voh', locations=[('main.py', 1)])
+        catalog.add('foo', 'Voh', locations=[('main.py', 1)])
         msgid = r"""Here's a message that covers
 multiple lines, and should still be handled
 correctly.
@@ -687,8 +689,8 @@ msgstr "Voh"
 
     def test_po_with_obsolete_message_ignored(self):
         catalog = Catalog()
-        catalog.add(u'foo', u'Voh', locations=[('main.py', 1)])
-        catalog.obsolete['bar'] = Message(u'bar', u'Bahr',
+        catalog.add('foo', 'Voh', locations=[('main.py', 1)])
+        catalog.obsolete['bar'] = Message('bar', 'Bahr',
                                           locations=[('utils.py', 3)],
                                           user_comments=['User comment'])
         buf = BytesIO()
@@ -699,8 +701,8 @@ msgstr "Voh"'''
 
     def test_po_with_previous_msgid(self):
         catalog = Catalog()
-        catalog.add(u'foo', u'Voh', locations=[('main.py', 1)],
-                    previous_id=u'fo')
+        catalog.add('foo', 'Voh', locations=[('main.py', 1)],
+                    previous_id='fo')
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=True, include_previous=True)
         assert buf.getvalue().strip() == b'''#: main.py:1
@@ -710,8 +712,8 @@ msgstr "Voh"'''
 
     def test_po_with_previous_msgid_plural(self):
         catalog = Catalog()
-        catalog.add((u'foo', u'foos'), (u'Voh', u'Voeh'),
-                    locations=[('main.py', 1)], previous_id=(u'fo', u'fos'))
+        catalog.add(('foo', 'foos'), ('Voh', 'Voeh'),
+                    locations=[('main.py', 1)], previous_id=('fo', 'fos'))
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=True, include_previous=True)
         assert buf.getvalue().strip() == b'''#: main.py:1
@@ -724,10 +726,10 @@ msgstr[1] "Voeh"'''
 
     def test_sorted_po(self):
         catalog = Catalog()
-        catalog.add(u'bar', locations=[('utils.py', 3)],
+        catalog.add('bar', locations=[('utils.py', 3)],
                     user_comments=['Comment About `bar` with',
                                    'multiple lines.'])
-        catalog.add((u'foo', u'foos'), (u'Voh', u'Voeh'),
+        catalog.add(('foo', 'foos'), ('Voh', 'Voeh'),
                     locations=[('main.py', 1)])
         buf = BytesIO()
         pofile.write_po(buf, catalog, sort_output=True)
@@ -748,12 +750,12 @@ msgstr[1] "Voeh"''' in value
 
     def test_sorted_po_context(self):
         catalog = Catalog()
-        catalog.add((u'foo', u'foos'), (u'Voh', u'Voeh'),
+        catalog.add(('foo', 'foos'), ('Voh', 'Voeh'),
                     locations=[('main.py', 1)],
                     context='there')
-        catalog.add((u'foo', u'foos'), (u'Voh', u'Voeh'),
+        catalog.add(('foo', 'foos'), ('Voh', 'Voeh'),
                     locations=[('main.py', 1)])
-        catalog.add((u'foo', u'foos'), (u'Voh', u'Voeh'),
+        catalog.add(('foo', 'foos'), ('Voh', 'Voeh'),
                     locations=[('main.py', 1)],
                     context='here')
         buf = BytesIO()
@@ -783,8 +785,8 @@ msgstr[1] "Voeh"''' in value
 
     def test_file_sorted_po(self):
         catalog = Catalog()
-        catalog.add(u'bar', locations=[('utils.py', 3)])
-        catalog.add((u'foo', u'foos'), (u'Voh', u'Voeh'), locations=[('main.py', 1)])
+        catalog.add('bar', locations=[('utils.py', 3)])
+        catalog.add(('foo', 'foos'), ('Voh', 'Voeh'), locations=[('main.py', 1)])
         buf = BytesIO()
         pofile.write_po(buf, catalog, sort_by_file=True)
         value = buf.getvalue().strip()
@@ -792,7 +794,7 @@ msgstr[1] "Voeh"''' in value
 
     def test_file_with_no_lineno(self):
         catalog = Catalog()
-        catalog.add(u'bar', locations=[('utils.py', None)],
+        catalog.add('bar', locations=[('utils.py', None)],
                     user_comments=['Comment About `bar` with',
                                    'multiple lines.'])
         buf = BytesIO()
@@ -820,8 +822,8 @@ msgstr ""''')
 
     def test_include_lineno(self):
         catalog = Catalog()
-        catalog.add(u'foo', locations=[('main.py', 1)])
-        catalog.add(u'foo', locations=[('utils.py', 3)])
+        catalog.add('foo', locations=[('main.py', 1)])
+        catalog.add('foo', locations=[('utils.py', 3)])
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=True, include_lineno=True)
         assert buf.getvalue().strip() == b'''#: main.py:1 utils.py:3
@@ -830,9 +832,9 @@ msgstr ""'''
 
     def test_no_include_lineno(self):
         catalog = Catalog()
-        catalog.add(u'foo', locations=[('main.py', 1)])
-        catalog.add(u'foo', locations=[('main.py', 2)])
-        catalog.add(u'foo', locations=[('utils.py', 3)])
+        catalog.add('foo', locations=[('main.py', 1)])
+        catalog.add('foo', locations=[('main.py', 2)])
+        catalog.add('foo', locations=[('utils.py', 3)])
         buf = BytesIO()
         pofile.write_po(buf, catalog, omit_header=True, include_lineno=False)
         assert buf.getvalue().strip() == b'''#: main.py utils.py
@@ -843,8 +845,8 @@ msgstr ""'''
 class PofileFunctionsTestCase(unittest.TestCase):
 
     def test_unescape(self):
-        escaped = u'"Say:\\n  \\"hello, world!\\"\\n"'
-        unescaped = u'Say:\n  "hello, world!"\n'
+        escaped = '"Say:\\n  \\"hello, world!\\"\\n"'
+        unescaped = 'Say:\n  "hello, world!"\n'
         assert unescaped != escaped
         assert unescaped == pofile.unescape(escaped)
 
@@ -856,7 +858,7 @@ class PofileFunctionsTestCase(unittest.TestCase):
         # handle irregular multi-line msgstr (no "" as first line)
         # gracefully (#171)
         msgstr = '"multi-line\\n"\n" translation"'
-        expected_denormalized = u'multi-line\n translation'
+        expected_denormalized = 'multi-line\n translation'
 
         assert expected_denormalized == pofile.denormalize(msgstr)
         assert expected_denormalized == pofile.denormalize(f'""\n{msgstr}')
diff --git a/tests/test_core.py b/tests/test_core.py
index 605bf5c..d315018 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -13,20 +13,19 @@
 import pytest
 
 from babel import core
-from babel.core import default_locale, Locale
+from babel.core import Locale, default_locale
 
 
 def test_locale_provides_access_to_cldr_locale_data():
     locale = Locale('en', 'US')
-    assert u'English (United States)' == locale.display_name
-    assert u'.' == locale.number_symbols['decimal']
+    assert locale.display_name == 'English (United States)'
+    assert locale.number_symbols['decimal'] == '.'
 
 
 def test_locale_repr():
     assert repr(Locale('en', 'US')) == "Locale('en', territory='US')"
-    assert ("Locale('de', territory='DE')" == repr(Locale('de', 'DE')))
-    assert ("Locale('zh', territory='CN', script='Hans')" ==
-            repr(Locale('zh', 'CN', script='Hans')))
+    assert (repr(Locale('de', 'DE')) == "Locale('de', territory='DE')")
+    assert (repr(Locale('zh', 'CN', script='Hans')) == "Locale('zh', territory='CN', script='Hans')")
 
 
 def test_locale_comparison():
@@ -97,36 +96,36 @@ class TestLocaleClass:
         assert (de_DE.language, de_DE.territory) == ('de', 'DE')
 
     def test_parse(self):
-        l = Locale.parse('de-DE', sep='-')
-        assert l.display_name == 'Deutsch (Deutschland)'
+        locale = Locale.parse('de-DE', sep='-')
+        assert locale.display_name == 'Deutsch (Deutschland)'
 
-        de_DE = Locale.parse(l)
+        de_DE = Locale.parse(locale)
         assert (de_DE.language, de_DE.territory) == ('de', 'DE')
 
     def test_parse_likely_subtags(self):
-        l = Locale.parse('zh-TW', sep='-')
-        assert l.language == 'zh'
-        assert l.territory == 'TW'
-        assert l.script == 'Hant'
-
-        l = Locale.parse('zh_CN')
-        assert l.language == 'zh'
-        assert l.territory == 'CN'
-        assert l.script == 'Hans'
-
-        l = Locale.parse('zh_SG')
-        assert l.language == 'zh'
-        assert l.territory == 'SG'
-        assert l.script == 'Hans'
-
-        l = Locale.parse('und_AT')
-        assert l.language == 'de'
-        assert l.territory == 'AT'
-
-        l = Locale.parse('und_UK')
-        assert l.language == 'en'
-        assert l.territory == 'GB'
-        assert l.script is None
+        locale = Locale.parse('zh-TW', sep='-')
+        assert locale.language == 'zh'
+        assert locale.territory == 'TW'
+        assert locale.script == 'Hant'
+
+        locale = Locale.parse('zh_CN')
+        assert locale.language == 'zh'
+        assert locale.territory == 'CN'
+        assert locale.script == 'Hans'
+
+        locale = Locale.parse('zh_SG')
+        assert locale.language == 'zh'
+        assert locale.territory == 'SG'
+        assert locale.script == 'Hans'
+
+        locale = Locale.parse('und_AT')
+        assert locale.language == 'de'
+        assert locale.territory == 'AT'
+
+        locale = Locale.parse('und_UK')
+        assert locale.language == 'en'
+        assert locale.territory == 'GB'
+        assert locale.script is None
 
     def test_get_display_name(self):
         zh_CN = Locale('zh', 'CN', script='Hans')
@@ -170,9 +169,9 @@ class TestLocaleClass:
 
     def test_currency_formats_property(self):
         assert (Locale('en', 'US').currency_formats['standard'].pattern ==
-                u'\xa4#,##0.00')
+                '\xa4#,##0.00')
         assert (Locale('en', 'US').currency_formats['accounting'].pattern ==
-                u'\xa4#,##0.00;(\xa4#,##0.00)')
+                '\xa4#,##0.00;(\xa4#,##0.00)')
 
     def test_percent_formats_property(self):
         assert Locale('en', 'US').percent_formats[None].pattern == '#,##0%'
@@ -200,7 +199,7 @@ class TestLocaleClass:
         time_zones = Locale('en', 'US').time_zones
         assert (time_zones['Europe/London']['long']['daylight'] ==
                 'British Summer Time')
-        assert time_zones['America/St_Johns']['city'] == u'St. John\u2019s'
+        assert time_zones['America/St_Johns']['city'] == 'St. John\u2019s'
 
     def test_meta_zones_property(self):
         meta_zones = Locale('en', 'US').meta_zones
@@ -209,7 +208,7 @@ class TestLocaleClass:
 
     def test_zone_formats_property(self):
         assert Locale('en', 'US').zone_formats['fallback'] == '%(1)s (%(0)s)'
-        assert Locale('pt', 'BR').zone_formats['region'] == u'Hor\xe1rio %s'
+        assert Locale('pt', 'BR').zone_formats['region'] == 'Hor\xe1rio %s'
 
     def test_first_week_day_property(self):
         assert Locale('de', 'DE').first_week_day == 0
@@ -233,12 +232,12 @@ class TestLocaleClass:
         assert Locale('fr', 'FR').time_formats['long'].pattern == 'HH:mm:ss z'
 
     def test_datetime_formats_property(self):
-        assert Locale('en').datetime_formats['full'] == u"{1} 'at' {0}"
-        assert Locale('th').datetime_formats['medium'] == u'{1} {0}'
+        assert Locale('en').datetime_formats['full'] == "{1} 'at' {0}"
+        assert Locale('th').datetime_formats['medium'] == '{1} {0}'
 
     def test_datetime_skeleton_property(self):
-        assert Locale('en').datetime_skeletons['Md'].pattern == u"M/d"
-        assert Locale('th').datetime_skeletons['Md'].pattern == u'd/M'
+        assert Locale('en').datetime_skeletons['Md'].pattern == "M/d"
+        assert Locale('th').datetime_skeletons['Md'].pattern == 'd/M'
 
     def test_plural_form_property(self):
         assert Locale('en').plural_form(1) == 'one'
@@ -322,7 +321,7 @@ def test_issue_601_no_language_name_but_has_variant():
     # Instead, it's better to return None altogether, as we can't reliably format
     # part of a language name.
 
-    assert Locale.parse('fi_FI').get_display_name('kw_GB') == None
+    assert Locale.parse('fi_FI').get_display_name('kw_GB') is None
 
 
 def test_issue_814():
diff --git a/tests/test_date_intervals.py b/tests/test_date_intervals.py
index 8e84a9e..5565854 100644
--- a/tests/test_date_intervals.py
+++ b/tests/test_date_intervals.py
@@ -46,8 +46,8 @@ def test_format_interval_12_hour():
 def test_format_interval_invalid_skeleton():
     t1 = TEST_DATE
     t2 = TEST_DATE + datetime.timedelta(days=1)
-    assert dates.format_interval(t1, t2, "mumumu", fuzzy=False, locale="fi") == u"8.1.2016\u20139.1.2016"
-    assert dates.format_interval(t1, t2, fuzzy=False, locale="fi") == u"8.1.2016\u20139.1.2016"
+    assert dates.format_interval(t1, t2, "mumumu", fuzzy=False, locale="fi") == "8.1.2016\u20139.1.2016"
+    assert dates.format_interval(t1, t2, fuzzy=False, locale="fi") == "8.1.2016\u20139.1.2016"
 
 
 def test_issue_825():
diff --git a/tests/test_dates.py b/tests/test_dates.py
index a4fb9c5..0c8bd17 100644
--- a/tests/test_dates.py
+++ b/tests/test_dates.py
@@ -16,7 +16,7 @@ from datetime import date, datetime, time, timedelta
 import freezegun
 import pytest
 
-from babel import dates, Locale
+from babel import Locale, dates
 from babel.dates import NO_INHERITANCE_MARKER, _localize
 from babel.util import FixedOffsetTimezone
 
@@ -68,7 +68,7 @@ class DateTimeFormatTestCase:
         assert dates.DateTimeFormat(d, locale='en_US')['w'] == '53'
 
     def test_week_of_year_de_first_us_last_with_year(self):
-        d = date(2018,12,31)
+        d = date(2018, 12, 31)
         fmt = dates.DateTimeFormat(d, locale='de_DE')
         assert fmt['w'] == '1'
         assert fmt['YYYY'] == '2019'
@@ -213,20 +213,20 @@ class DateTimeFormatTestCase:
     def test_timezone_walltime_long(self, timezone_getter):
         tz = timezone_getter('Europe/Paris')
         t = time(15, 30, tzinfo=tz)
-        assert dates.DateTimeFormat(t, locale='fr_FR')['vvvv'] == u'heure d’Europe centrale'
+        assert dates.DateTimeFormat(t, locale='fr_FR')['vvvv'] == 'heure d’Europe centrale'
 
     def test_hour_formatting(self):
-        l = 'en_US'
+        locale = 'en_US'
         t = time(0, 0, 0)
-        assert dates.format_time(t, 'h a', locale=l) == '12 AM'
-        assert dates.format_time(t, 'H', locale=l) == '0'
-        assert dates.format_time(t, 'k', locale=l) == '24'
-        assert dates.format_time(t, 'K a', locale=l) == '0 AM'
+        assert dates.format_time(t, 'h a', locale=locale) == '12 AM'
+        assert dates.format_time(t, 'H', locale=locale) == '0'
+        assert dates.format_time(t, 'k', locale=locale) == '24'
+        assert dates.format_time(t, 'K a', locale=locale) == '0 AM'
         t = time(12, 0, 0)
-        assert dates.format_time(t, 'h a', locale=l) == '12 PM'
-        assert dates.format_time(t, 'H', locale=l) == '12'
-        assert dates.format_time(t, 'k', locale=l) == '12'
-        assert dates.format_time(t, 'K a', locale=l) == '0 PM'
+        assert dates.format_time(t, 'h a', locale=locale) == '12 PM'
+        assert dates.format_time(t, 'H', locale=locale) == '12'
+        assert dates.format_time(t, 'k', locale=locale) == '12'
+        assert dates.format_time(t, 'K a', locale=locale) == '0 PM'
 
 
 class FormatDateTestCase:
@@ -252,75 +252,75 @@ class FormatDatetimeTestCase:
         d = datetime(2012, 4, 1, 15, 30, 29, tzinfo=UTC)
         epoch = float(calendar.timegm(d.timetuple()))
         formatted_string = dates.format_datetime(epoch, format='long', locale='en_US')
-        assert formatted_string == u'April 1, 2012 at 3:30:29 PM UTC'
+        assert formatted_string == 'April 1, 2012 at 3:30:29 PM UTC'
 
     def test_timezone_formats_los_angeles(self, timezone_getter):
         tz = timezone_getter('America/Los_Angeles')
         dt = _localize(tz, datetime(2016, 1, 13, 7, 8, 35))
-        assert dates.format_datetime(dt, 'z', locale='en') == u'PST'
-        assert dates.format_datetime(dt, 'zz', locale='en') == u'PST'
-        assert dates.format_datetime(dt, 'zzz', locale='en') == u'PST'
-        assert dates.format_datetime(dt, 'zzzz', locale='en') == u'Pacific Standard Time'
-        assert dates.format_datetime(dt, 'Z', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'ZZ', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'ZZZ', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'ZZZZ', locale='en') == u'GMT-08:00'
-        assert dates.format_datetime(dt, 'ZZZZZ', locale='en') == u'-08:00'
-        assert dates.format_datetime(dt, 'OOOO', locale='en') == u'GMT-08:00'
-        assert dates.format_datetime(dt, 'VV', locale='en') == u'America/Los_Angeles'
-        assert dates.format_datetime(dt, 'VVV', locale='en') == u'Los Angeles'
-        assert dates.format_datetime(dt, 'X', locale='en') == u'-08'
-        assert dates.format_datetime(dt, 'XX', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'XXX', locale='en') == u'-08:00'
-        assert dates.format_datetime(dt, 'XXXX', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'XXXXX', locale='en') == u'-08:00'
-        assert dates.format_datetime(dt, 'x', locale='en') == u'-08'
-        assert dates.format_datetime(dt, 'xx', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'xxx', locale='en') == u'-08:00'
-        assert dates.format_datetime(dt, 'xxxx', locale='en') == u'-0800'
-        assert dates.format_datetime(dt, 'xxxxx', locale='en') == u'-08:00'
+        assert dates.format_datetime(dt, 'z', locale='en') == 'PST'
+        assert dates.format_datetime(dt, 'zz', locale='en') == 'PST'
+        assert dates.format_datetime(dt, 'zzz', locale='en') == 'PST'
+        assert dates.format_datetime(dt, 'zzzz', locale='en') == 'Pacific Standard Time'
+        assert dates.format_datetime(dt, 'Z', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'ZZ', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'ZZZ', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'ZZZZ', locale='en') == 'GMT-08:00'
+        assert dates.format_datetime(dt, 'ZZZZZ', locale='en') == '-08:00'
+        assert dates.format_datetime(dt, 'OOOO', locale='en') == 'GMT-08:00'
+        assert dates.format_datetime(dt, 'VV', locale='en') == 'America/Los_Angeles'
+        assert dates.format_datetime(dt, 'VVV', locale='en') == 'Los Angeles'
+        assert dates.format_datetime(dt, 'X', locale='en') == '-08'
+        assert dates.format_datetime(dt, 'XX', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'XXX', locale='en') == '-08:00'
+        assert dates.format_datetime(dt, 'XXXX', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'XXXXX', locale='en') == '-08:00'
+        assert dates.format_datetime(dt, 'x', locale='en') == '-08'
+        assert dates.format_datetime(dt, 'xx', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'xxx', locale='en') == '-08:00'
+        assert dates.format_datetime(dt, 'xxxx', locale='en') == '-0800'
+        assert dates.format_datetime(dt, 'xxxxx', locale='en') == '-08:00'
 
     def test_timezone_formats_utc(self, timezone_getter):
         tz = timezone_getter('UTC')
         dt = _localize(tz, datetime(2016, 1, 13, 7, 8, 35))
-        assert dates.format_datetime(dt, 'Z', locale='en') == u'+0000'
-        assert dates.format_datetime(dt, 'ZZ', locale='en') == u'+0000'
-        assert dates.format_datetime(dt, 'ZZZ', locale='en') == u'+0000'
-        assert dates.format_datetime(dt, 'ZZZZ', locale='en') == u'GMT+00:00'
-        assert dates.format_datetime(dt, 'ZZZZZ', locale='en') == u'Z'
-        assert dates.format_datetime(dt, 'OOOO', locale='en') == u'GMT+00:00'
-        assert dates.format_datetime(dt, 'VV', locale='en') == u'Etc/UTC'
-        assert dates.format_datetime(dt, 'VVV', locale='en') == u'UTC'
-        assert dates.format_datetime(dt, 'X', locale='en') == u'Z'
-        assert dates.format_datetime(dt, 'XX', locale='en') == u'Z'
-        assert dates.format_datetime(dt, 'XXX', locale='en') == u'Z'
-        assert dates.format_datetime(dt, 'XXXX', locale='en') == u'Z'
-        assert dates.format_datetime(dt, 'XXXXX', locale='en') == u'Z'
-        assert dates.format_datetime(dt, 'x', locale='en') == u'+00'
-        assert dates.format_datetime(dt, 'xx', locale='en') == u'+0000'
-        assert dates.format_datetime(dt, 'xxx', locale='en') == u'+00:00'
-        assert dates.format_datetime(dt, 'xxxx', locale='en') == u'+0000'
-        assert dates.format_datetime(dt, 'xxxxx', locale='en') == u'+00:00'
+        assert dates.format_datetime(dt, 'Z', locale='en') == '+0000'
+        assert dates.format_datetime(dt, 'ZZ', locale='en') == '+0000'
+        assert dates.format_datetime(dt, 'ZZZ', locale='en') == '+0000'
+        assert dates.format_datetime(dt, 'ZZZZ', locale='en') == 'GMT+00:00'
+        assert dates.format_datetime(dt, 'ZZZZZ', locale='en') == 'Z'
+        assert dates.format_datetime(dt, 'OOOO', locale='en') == 'GMT+00:00'
+        assert dates.format_datetime(dt, 'VV', locale='en') == 'Etc/UTC'
+        assert dates.format_datetime(dt, 'VVV', locale='en') == 'UTC'
+        assert dates.format_datetime(dt, 'X', locale='en') == 'Z'
+        assert dates.format_datetime(dt, 'XX', locale='en') == 'Z'
+        assert dates.format_datetime(dt, 'XXX', locale='en') == 'Z'
+        assert dates.format_datetime(dt, 'XXXX', locale='en') == 'Z'
+        assert dates.format_datetime(dt, 'XXXXX', locale='en') == 'Z'
+        assert dates.format_datetime(dt, 'x', locale='en') == '+00'
+        assert dates.format_datetime(dt, 'xx', locale='en') == '+0000'
+        assert dates.format_datetime(dt, 'xxx', locale='en') == '+00:00'
+        assert dates.format_datetime(dt, 'xxxx', locale='en') == '+0000'
+        assert dates.format_datetime(dt, 'xxxxx', locale='en') == '+00:00'
 
     def test_timezone_formats_kolkata(self, timezone_getter):
         tz = timezone_getter('Asia/Kolkata')
         dt = _localize(tz, datetime(2016, 1, 13, 7, 8, 35))
-        assert dates.format_datetime(dt, 'zzzz', locale='en') == u'India Standard Time'
-        assert dates.format_datetime(dt, 'ZZZZ', locale='en') == u'GMT+05:30'
-        assert dates.format_datetime(dt, 'ZZZZZ', locale='en') == u'+05:30'
-        assert dates.format_datetime(dt, 'OOOO', locale='en') == u'GMT+05:30'
-        assert dates.format_datetime(dt, 'VV', locale='en') == u'Asia/Calcutta'
-        assert dates.format_datetime(dt, 'VVV', locale='en') == u'Kolkata'
-        assert dates.format_datetime(dt, 'X', locale='en') == u'+0530'
-        assert dates.format_datetime(dt, 'XX', locale='en') == u'+0530'
-        assert dates.format_datetime(dt, 'XXX', locale='en') == u'+05:30'
-        assert dates.format_datetime(dt, 'XXXX', locale='en') == u'+0530'
-        assert dates.format_datetime(dt, 'XXXXX', locale='en') == u'+05:30'
-        assert dates.format_datetime(dt, 'x', locale='en') == u'+0530'
-        assert dates.format_datetime(dt, 'xx', locale='en') == u'+0530'
-        assert dates.format_datetime(dt, 'xxx', locale='en') == u'+05:30'
-        assert dates.format_datetime(dt, 'xxxx', locale='en') == u'+0530'
-        assert dates.format_datetime(dt, 'xxxxx', locale='en') == u'+05:30'
+        assert dates.format_datetime(dt, 'zzzz', locale='en') == 'India Standard Time'
+        assert dates.format_datetime(dt, 'ZZZZ', locale='en') == 'GMT+05:30'
+        assert dates.format_datetime(dt, 'ZZZZZ', locale='en') == '+05:30'
+        assert dates.format_datetime(dt, 'OOOO', locale='en') == 'GMT+05:30'
+        assert dates.format_datetime(dt, 'VV', locale='en') == 'Asia/Calcutta'
+        assert dates.format_datetime(dt, 'VVV', locale='en') == 'Kolkata'
+        assert dates.format_datetime(dt, 'X', locale='en') == '+0530'
+        assert dates.format_datetime(dt, 'XX', locale='en') == '+0530'
+        assert dates.format_datetime(dt, 'XXX', locale='en') == '+05:30'
+        assert dates.format_datetime(dt, 'XXXX', locale='en') == '+0530'
+        assert dates.format_datetime(dt, 'XXXXX', locale='en') == '+05:30'
+        assert dates.format_datetime(dt, 'x', locale='en') == '+0530'
+        assert dates.format_datetime(dt, 'xx', locale='en') == '+0530'
+        assert dates.format_datetime(dt, 'xxx', locale='en') == '+05:30'
+        assert dates.format_datetime(dt, 'xxxx', locale='en') == '+0530'
+        assert dates.format_datetime(dt, 'xxxxx', locale='en') == '+05:30'
 
 
 class FormatTimeTestCase:
@@ -337,7 +337,7 @@ class FormatTimeTestCase:
         tz = timezone_getter('UTC')
         d = _localize(tz, datetime(2012, 4, 1, 15, 30, 29))
         epoch = float(calendar.timegm(d.timetuple()))
-        assert dates.format_time(epoch, format='long', locale='en_US') == u'3:30:29 PM UTC'
+        assert dates.format_time(epoch, format='long', locale='en_US') == '3:30:29 PM UTC'
 
     def test_with_date_fields_in_pattern(self):
         with pytest.raises(AttributeError):
@@ -398,122 +398,122 @@ class TimeZoneAdjustTestCase:
 
 
 def test_get_period_names():
-    assert dates.get_period_names(locale='en_US')['am'] == u'AM'
+    assert dates.get_period_names(locale='en_US')['am'] == 'AM'
 
 
 def test_get_day_names():
-    assert dates.get_day_names('wide', locale='en_US')[1] == u'Tuesday'
-    assert dates.get_day_names('short', locale='en_US')[1] == u'Tu'
-    assert dates.get_day_names('abbreviated', locale='es')[1] == u'mar'
+    assert dates.get_day_names('wide', locale='en_US')[1] == 'Tuesday'
+    assert dates.get_day_names('short', locale='en_US')[1] == 'Tu'
+    assert dates.get_day_names('abbreviated', locale='es')[1] == 'mar'
     de = dates.get_day_names('narrow', context='stand-alone', locale='de_DE')
-    assert de[1] == u'D'
+    assert de[1] == 'D'
 
 
 def test_get_month_names():
-    assert dates.get_month_names('wide', locale='en_US')[1] == u'January'
-    assert dates.get_month_names('abbreviated', locale='es')[1] == u'ene'
+    assert dates.get_month_names('wide', locale='en_US')[1] == 'January'
+    assert dates.get_month_names('abbreviated', locale='es')[1] == 'ene'
     de = dates.get_month_names('narrow', context='stand-alone', locale='de_DE')
-    assert de[1] == u'J'
+    assert de[1] == 'J'
 
 
 def test_get_quarter_names():
-    assert dates.get_quarter_names('wide', locale='en_US')[1] == u'1st quarter'
-    assert dates.get_quarter_names('abbreviated', locale='de_DE')[1] == u'Q1'
-    assert dates.get_quarter_names('narrow', locale='de_DE')[1] == u'1'
+    assert dates.get_quarter_names('wide', locale='en_US')[1] == '1st quarter'
+    assert dates.get_quarter_names('abbreviated', locale='de_DE')[1] == 'Q1'
+    assert dates.get_quarter_names('narrow', locale='de_DE')[1] == '1'
 
 
 def test_get_era_names():
-    assert dates.get_era_names('wide', locale='en_US')[1] == u'Anno Domini'
-    assert dates.get_era_names('abbreviated', locale='de_DE')[1] == u'n. Chr.'
+    assert dates.get_era_names('wide', locale='en_US')[1] == 'Anno Domini'
+    assert dates.get_era_names('abbreviated', locale='de_DE')[1] == 'n. Chr.'
 
 
 def test_get_date_format():
     us = dates.get_date_format(locale='en_US')
-    assert us.pattern == u'MMM d, y'
+    assert us.pattern == 'MMM d, y'
     de = dates.get_date_format('full', locale='de_DE')
-    assert de.pattern == u'EEEE, d. MMMM y'
+    assert de.pattern == 'EEEE, d. MMMM y'
 
 
 def test_get_datetime_format():
-    assert dates.get_datetime_format(locale='en_US') == u'{1}, {0}'
+    assert dates.get_datetime_format(locale='en_US') == '{1}, {0}'
 
 
 def test_get_time_format():
-    assert dates.get_time_format(locale='en_US').pattern == u'h:mm:ss a'
+    assert dates.get_time_format(locale='en_US').pattern == 'h:mm:ss a'
     assert (dates.get_time_format('full', locale='de_DE').pattern ==
-            u'HH:mm:ss zzzz')
+            'HH:mm:ss zzzz')
 
 
 def test_get_timezone_gmt(timezone_getter):
     dt = datetime(2007, 4, 1, 15, 30)
-    assert dates.get_timezone_gmt(dt, locale='en') == u'GMT+00:00'
+    assert dates.get_timezone_gmt(dt, locale='en') == 'GMT+00:00'
     assert dates.get_timezone_gmt(dt, locale='en', return_z=True) == 'Z'
-    assert dates.get_timezone_gmt(dt, locale='en', width='iso8601_short') == u'+00'
+    assert dates.get_timezone_gmt(dt, locale='en', width='iso8601_short') == '+00'
     tz = timezone_getter('America/Los_Angeles')
     dt = _localize(tz, datetime(2007, 4, 1, 15, 30))
-    assert dates.get_timezone_gmt(dt, locale='en') == u'GMT-07:00'
-    assert dates.get_timezone_gmt(dt, 'short', locale='en') == u'-0700'
-    assert dates.get_timezone_gmt(dt, locale='en', width='iso8601_short') == u'-07'
-    assert dates.get_timezone_gmt(dt, 'long', locale='fr_FR') == u'UTC-07:00'
+    assert dates.get_timezone_gmt(dt, locale='en') == 'GMT-07:00'
+    assert dates.get_timezone_gmt(dt, 'short', locale='en') == '-0700'
+    assert dates.get_timezone_gmt(dt, locale='en', width='iso8601_short') == '-07'
+    assert dates.get_timezone_gmt(dt, 'long', locale='fr_FR') == 'UTC-07:00'
 
 
 def test_get_timezone_location(timezone_getter):
     tz = timezone_getter('America/St_Johns')
     assert (dates.get_timezone_location(tz, locale='de_DE') ==
-            u"Kanada (St. John\u2019s) Zeit")
+            "Kanada (St. John\u2019s) Zeit")
     assert (dates.get_timezone_location(tz, locale='en') ==
-            u'Canada (St. John’s) Time')
+            'Canada (St. John’s) Time')
     assert (dates.get_timezone_location(tz, locale='en', return_city=True) ==
-            u'St. John’s')
+            'St. John’s')
 
     tz = timezone_getter('America/Mexico_City')
     assert (dates.get_timezone_location(tz, locale='de_DE') ==
-            u'Mexiko (Mexiko-Stadt) Zeit')
+            'Mexiko (Mexiko-Stadt) Zeit')
 
     tz = timezone_getter('Europe/Berlin')
     assert (dates.get_timezone_location(tz, locale='de_DE') ==
-            u'Deutschland (Berlin) Zeit')
+            'Deutschland (Berlin) Zeit')
 
 
 @pytest.mark.parametrize(
     "tzname, params, expected",
     [
-        ("America/Los_Angeles", {"locale": "en_US"}, u"Pacific Time"),
-        ("America/Los_Angeles", {"width": "short", "locale": "en_US"}, u"PT"),
-        ("Europe/Berlin", {"locale": "de_DE"}, u"Mitteleurop\xe4ische Zeit"),
-        ("Europe/Berlin", {"locale": "pt_BR"}, u"Hor\xe1rio da Europa Central"),
-        ("America/St_Johns", {"locale": "de_DE"}, u"Neufundland-Zeit"),
+        ("America/Los_Angeles", {"locale": "en_US"}, "Pacific Time"),
+        ("America/Los_Angeles", {"width": "short", "locale": "en_US"}, "PT"),
+        ("Europe/Berlin", {"locale": "de_DE"}, "Mitteleurop\xe4ische Zeit"),
+        ("Europe/Berlin", {"locale": "pt_BR"}, "Hor\xe1rio da Europa Central"),
+        ("America/St_Johns", {"locale": "de_DE"}, "Neufundland-Zeit"),
         (
             "America/Los_Angeles",
             {"locale": "en", "width": "short", "zone_variant": "generic"},
-            u"PT",
+            "PT",
         ),
         (
             "America/Los_Angeles",
             {"locale": "en", "width": "short", "zone_variant": "standard"},
-            u"PST",
+            "PST",
         ),
         (
             "America/Los_Angeles",
             {"locale": "en", "width": "short", "zone_variant": "daylight"},
-            u"PDT",
+            "PDT",
         ),
         (
             "America/Los_Angeles",
             {"locale": "en", "width": "long", "zone_variant": "generic"},
-            u"Pacific Time",
+            "Pacific Time",
         ),
         (
             "America/Los_Angeles",
             {"locale": "en", "width": "long", "zone_variant": "standard"},
-            u"Pacific Standard Time",
+            "Pacific Standard Time",
         ),
         (
             "America/Los_Angeles",
             {"locale": "en", "width": "long", "zone_variant": "daylight"},
-            u"Pacific Daylight Time",
+            "Pacific Daylight Time",
         ),
-        ("Europe/Berlin", {"locale": "en_US"}, u"Central European Time"),
+        ("Europe/Berlin", {"locale": "en_US"}, "Central European Time"),
     ],
 )
 def test_get_timezone_name_tzinfo(timezone_getter, tzname, params, expected):
@@ -525,13 +525,13 @@ def test_get_timezone_name_tzinfo(timezone_getter, tzname, params, expected):
 @pytest.mark.parametrize(
     "tzname, params, expected",
     [
-        ("America/Los_Angeles", {"locale": "en_US"}, u"Pacific Standard Time"),
+        ("America/Los_Angeles", {"locale": "en_US"}, "Pacific Standard Time"),
         (
             "America/Los_Angeles",
             {"locale": "en_US", "return_zone": True},
-            u"America/Los_Angeles",
+            "America/Los_Angeles",
         ),
-        ("America/Los_Angeles", {"width": "short", "locale": "en_US"}, u"PST"),
+        ("America/Los_Angeles", {"width": "short", "locale": "en_US"}, "PST"),
     ],
 )
 def test_get_timezone_name_time_pytz(timezone_getter, tzname, params, expected):
@@ -554,40 +554,42 @@ def test_get_timezone_name_misc(timezone_getter):
 
 def test_format_date():
     d = date(2007, 4, 1)
-    assert dates.format_date(d, locale='en_US') == u'Apr 1, 2007'
+    assert dates.format_date(d, locale='en_US') == 'Apr 1, 2007'
     assert (dates.format_date(d, format='full', locale='de_DE') ==
-            u'Sonntag, 1. April 2007')
+            'Sonntag, 1. April 2007')
     assert (dates.format_date(d, "EEE, MMM d, ''yy", locale='en') ==
-            u"Sun, Apr 1, '07")
+            "Sun, Apr 1, '07")
 
 
 def test_format_datetime(timezone_getter):
     dt = datetime(2007, 4, 1, 15, 30)
     assert (dates.format_datetime(dt, locale='en_US') ==
-            u'Apr 1, 2007, 3:30:00 PM')
+            'Apr 1, 2007, 3:30:00 PM')
 
     full = dates.format_datetime(
         dt, 'full',
         tzinfo=timezone_getter('Europe/Paris'),
         locale='fr_FR'
     )
-    assert full == (u'dimanche 1 avril 2007 à 17:30:00 heure '
-                    u'd\u2019\xe9t\xe9 d\u2019Europe centrale')
+    assert full == (
+        'dimanche 1 avril 2007 à 17:30:00 heure '
+        'd\u2019\xe9t\xe9 d\u2019Europe centrale'
+    )
     custom = dates.format_datetime(
         dt, "yyyy.MM.dd G 'at' HH:mm:ss zzz",
         tzinfo=timezone_getter('US/Eastern'),
         locale='en'
     )
-    assert custom == u'2007.04.01 AD at 11:30:00 EDT'
+    assert custom == '2007.04.01 AD at 11:30:00 EDT'
 
 
 def test_format_time(timezone_getter):
     t = time(15, 30)
-    assert dates.format_time(t, locale='en_US') == u'3:30:00 PM'
-    assert dates.format_time(t, format='short', locale='de_DE') == u'15:30'
+    assert dates.format_time(t, locale='en_US') == '3:30:00 PM'
+    assert dates.format_time(t, format='short', locale='de_DE') == '15:30'
 
     assert (dates.format_time(t, "hh 'o''clock' a", locale='en') ==
-            u"03 o'clock PM")
+            "03 o'clock PM")
 
     paris = timezone_getter('Europe/Paris')
     eastern = timezone_getter('US/Eastern')
@@ -597,41 +599,41 @@ def test_format_time(timezone_getter):
     assert fr == '15:30:00 heure d’été d’Europe centrale'
 
     custom = dates.format_time(t, "hh 'o''clock' a, zzzz", tzinfo=eastern, locale='en')
-    assert custom == u"09 o'clock AM, Eastern Daylight Time"
+    assert custom == "09 o'clock AM, Eastern Daylight Time"
 
     t = time(15, 30)
     paris = dates.format_time(t, format='full', tzinfo=paris, locale='fr_FR')
     assert paris == '15:30:00 heure normale d’Europe centrale'
 
     us_east = dates.format_time(t, format='full', tzinfo=eastern, locale='en_US')
-    assert us_east == u'3:30:00 PM Eastern Standard Time'
+    assert us_east == '3:30:00 PM Eastern Standard Time'
 
 
 def test_format_skeleton(timezone_getter):
     dt = datetime(2007, 4, 1, 15, 30)
-    assert (dates.format_skeleton('yMEd', dt, locale='en_US') == u'Sun, 4/1/2007')
-    assert (dates.format_skeleton('yMEd', dt, locale='th') == u'อา. 1/4/2007')
+    assert (dates.format_skeleton('yMEd', dt, locale='en_US') == 'Sun, 4/1/2007')
+    assert (dates.format_skeleton('yMEd', dt, locale='th') == 'อา. 1/4/2007')
 
-    assert (dates.format_skeleton('EHm', dt, locale='en') == u'Sun 15:30')
-    assert (dates.format_skeleton('EHm', dt, tzinfo=timezone_getter('Asia/Bangkok'), locale='th') == u'อา. 22:30 น.')
+    assert (dates.format_skeleton('EHm', dt, locale='en') == 'Sun 15:30')
+    assert (dates.format_skeleton('EHm', dt, tzinfo=timezone_getter('Asia/Bangkok'), locale='th') == 'อา. 22:30 น.')
 
 
 def test_format_timedelta():
     assert (dates.format_timedelta(timedelta(weeks=12), locale='en_US')
-            == u'3 months')
+            == '3 months')
     assert (dates.format_timedelta(timedelta(seconds=1), locale='es')
-            == u'1 segundo')
+            == '1 segundo')
 
     assert (dates.format_timedelta(timedelta(hours=3), granularity='day',
                                    locale='en_US')
-            == u'1 day')
+            == '1 day')
 
     assert (dates.format_timedelta(timedelta(hours=23), threshold=0.9,
                                    locale='en_US')
-            == u'1 day')
+            == '1 day')
     assert (dates.format_timedelta(timedelta(hours=23), threshold=1.1,
                                    locale='en_US')
-            == u'23 hours')
+            == '23 hours')
 
 
 def test_parse_date():
@@ -679,24 +681,24 @@ def test_datetime_format_get_week_number():
 
 
 def test_parse_pattern():
-    assert dates.parse_pattern("MMMMd").format == u'%(MMMM)s%(d)s'
+    assert dates.parse_pattern("MMMMd").format == '%(MMMM)s%(d)s'
     assert (dates.parse_pattern("MMM d, yyyy").format ==
-            u'%(MMM)s %(d)s, %(yyyy)s')
+            '%(MMM)s %(d)s, %(yyyy)s')
     assert (dates.parse_pattern("H:mm' Uhr 'z").format ==
-            u'%(H)s:%(mm)s Uhr %(z)s')
-    assert dates.parse_pattern("hh' o''clock'").format == u"%(hh)s o'clock"
+            '%(H)s:%(mm)s Uhr %(z)s')
+    assert dates.parse_pattern("hh' o''clock'").format == "%(hh)s o'clock"
 
 
 def test_lithuanian_long_format():
     assert (
         dates.format_date(date(2015, 12, 10), locale='lt_LT', format='long') ==
-        u'2015 m. gruodžio 10 d.'
+        '2015 m. gruodžio 10 d.'
     )
 
 
 def test_zh_TW_format():
     # Refs GitHub issue #378
-    assert dates.format_time(datetime(2016, 4, 8, 12, 34, 56), locale='zh_TW') == u'中午12:34:56'
+    assert dates.format_time(datetime(2016, 4, 8, 12, 34, 56), locale='zh_TW') == '中午12:34:56'
 
 
 def test_format_current_moment():
@@ -727,8 +729,8 @@ def test_no_inherit_metazone_formatting(timezone_getter):
 def test_russian_week_numbering():
     # See https://github.com/python-babel/babel/issues/485
     v = date(2017, 1, 1)
-    assert dates.format_date(v, format='YYYY-ww',locale='ru_RU') == '2016-52'  # This would have returned 2017-01 prior to CLDR 32
-    assert dates.format_date(v, format='YYYY-ww',locale='de_DE') == '2016-52'
+    assert dates.format_date(v, format='YYYY-ww', locale='ru_RU') == '2016-52'  # This would have returned 2017-01 prior to CLDR 32
+    assert dates.format_date(v, format='YYYY-ww', locale='de_DE') == '2016-52'
 
 
 def test_en_gb_first_weekday():
diff --git a/tests/test_day_periods.py b/tests/test_day_periods.py
index 414c0f6..9b51e1d 100644
--- a/tests/test_day_periods.py
+++ b/tests/test_day_periods.py
@@ -1,8 +1,9 @@
 from datetime import time
 
-import babel.dates as dates
 import pytest
 
+import babel.dates as dates
+
 
 @pytest.mark.parametrize("locale, time, expected_period_id", [
     ("de", time(7, 42), "morning1"),  # (from, before)
diff --git a/tests/test_lists.py b/tests/test_lists.py
index e51f18b..ca9c6ab 100644
--- a/tests/test_lists.py
+++ b/tests/test_lists.py
@@ -6,11 +6,11 @@ from babel import lists
 def test_format_list():
     for list, locale, expected in [
         ([], 'en', ''),
-        ([u'string'], 'en', u'string'),
-        (['string1', 'string2'], 'en', u'string1 and string2'),
-        (['string1', 'string2', 'string3'], 'en', u'string1, string2, and string3'),
-        (['string1', 'string2', 'string3'], 'zh', u'string1、string2和string3'),
-        (['string1', 'string2', 'string3', 'string4'], 'ne', u'string1,string2, string3 र string4'),
+        (['string'], 'en', 'string'),
+        (['string1', 'string2'], 'en', 'string1 and string2'),
+        (['string1', 'string2', 'string3'], 'en', 'string1, string2, and string3'),
+        (['string1', 'string2', 'string3'], 'zh', 'string1、string2和string3'),
+        (['string1', 'string2', 'string3', 'string4'], 'ne', 'string1,string2, string3 र string4'),
     ]:
         assert lists.format_list(list, locale=locale) == expected
 
diff --git a/tests/test_localedata.py b/tests/test_localedata.py
index 7bfe9c6..913922e 100644
--- a/tests/test_localedata.py
+++ b/tests/test_localedata.py
@@ -12,15 +12,15 @@
 
 import os
 import pickle
+import random
 import sys
 import tempfile
 import unittest
-import random
 from operator import methodcaller
 
 import pytest
 
-from babel import localedata, Locale, UnknownLocaleError
+from babel import Locale, UnknownLocaleError, localedata
 
 
 class MergeResolveTestCase(unittest.TestCase):
@@ -70,8 +70,8 @@ def test_merge():
 
 
 def test_locale_identification():
-    for l in localedata.locale_identifiers():
-        assert localedata.exists(l)
+    for locale in localedata.locale_identifiers():
+        assert localedata.exists(locale)
 
 
 def test_unique_ids():
@@ -84,9 +84,9 @@ def test_unique_ids():
 
 
 def test_mixedcased_locale():
-    for l in localedata.locale_identifiers():
+    for locale in localedata.locale_identifiers():
         locale_id = ''.join([
-            methodcaller(random.choice(['lower', 'upper']))(c) for c in l])
+            methodcaller(random.choice(['lower', 'upper']))(c) for c in locale])
         assert localedata.exists(locale_id)
 
 
@@ -94,19 +94,18 @@ def test_locale_argument_acceptance():
     # Testing None input.
     normalized_locale = localedata.normalize_locale(None)
     assert normalized_locale is None
-    locale_exist = localedata.exists(None)
-    assert locale_exist == False
+    assert not localedata.exists(None)
 
-    # # Testing list input.
+    # Testing list input.
     normalized_locale = localedata.normalize_locale(['en_us', None])
     assert normalized_locale is None
-    locale_exist = localedata.exists(['en_us', None])
-    assert locale_exist == False
+    assert not localedata.exists(['en_us', None])
 
 
 def test_locale_identifiers_cache(monkeypatch):
     original_listdir = localedata.os.listdir
     listdir_calls = []
+
     def listdir_spy(*args):
         rv = original_listdir(*args)
         listdir_calls.append((args, rv))
diff --git a/tests/test_numbers.py b/tests/test_numbers.py
index 0939562..04a1865 100644
--- a/tests/test_numbers.py
+++ b/tests/test_numbers.py
@@ -12,14 +12,21 @@
 
 import decimal
 import unittest
-import pytest
-
 from datetime import date
 
+import pytest
+
 from babel import localedata, numbers
 from babel.numbers import (
-    list_currencies, validate_currency, UnknownCurrencyError, is_currency, normalize_currency,
-    get_currency_precision, get_decimal_precision, get_currency_unit_pattern)
+    UnknownCurrencyError,
+    get_currency_precision,
+    get_currency_unit_pattern,
+    get_decimal_precision,
+    is_currency,
+    list_currencies,
+    normalize_currency,
+    validate_currency,
+)
 
 
 class FormatDecimalTestCase(unittest.TestCase):
@@ -31,7 +38,7 @@ class FormatDecimalTestCase(unittest.TestCase):
         # regression test for #183, fraction digits were not correctly cut
         # if the input was a float value and the value had more than 7
         # significant digits
-        assert numbers.format_decimal(12345678.051, '#,##0.00', locale='en_US') == u'12,345,678.05'
+        assert numbers.format_decimal(12345678.051, '#,##0.00', locale='en_US') == '12,345,678.05'
 
     def test_subpatterns(self):
         assert numbers.format_decimal((- 12345), '#,##0.##;-#', locale='en_US') == '-12,345'
@@ -108,57 +115,58 @@ class FormatDecimalTestCase(unittest.TestCase):
         assert numbers.format_decimal(29567.12, locale='en_US', group_separator=False) == '29567.12'
         assert numbers.format_decimal(29567.12, locale='fr_CA', group_separator=False) == '29567,12'
         assert numbers.format_decimal(29567.12, locale='pt_BR', group_separator=False) == '29567,12'
-        assert numbers.format_currency(1099.98, 'USD', locale='en_US', group_separator=False) == u'$1099.98'
-        assert numbers.format_currency(101299.98, 'EUR', locale='fr_CA', group_separator=False) == u'101299,98\xa0€'
+        assert numbers.format_currency(1099.98, 'USD', locale='en_US', group_separator=False) == '$1099.98'
+        assert numbers.format_currency(101299.98, 'EUR', locale='fr_CA', group_separator=False) == '101299,98\xa0€'
         assert numbers.format_currency(101299.98, 'EUR', locale='en_US', group_separator=False, format_type='name') == '101299.98 euros'
-        assert numbers.format_percent(251234.1234, locale='sv_SE', group_separator=False) == u'25123412\xa0%'
+        assert numbers.format_percent(251234.1234, locale='sv_SE', group_separator=False) == '25123412\xa0%'
 
-        assert numbers.format_decimal(29567.12, locale='en_US', group_separator=True) == u'29,567.12'
-        assert numbers.format_decimal(29567.12, locale='fr_CA', group_separator=True) == u'29\xa0567,12'
-        assert numbers.format_decimal(29567.12, locale='pt_BR', group_separator=True) == u'29.567,12'
-        assert numbers.format_currency(1099.98, 'USD', locale='en_US', group_separator=True) == u'$1,099.98'
-        assert numbers.format_currency(101299.98, 'EUR', locale='fr_CA', group_separator=True) == u'101\xa0299,98\xa0€'
-        assert numbers.format_currency(101299.98, 'EUR', locale='en_US', group_separator=True, format_type='name') == u'101,299.98 euros'
-        assert numbers.format_percent(251234.1234, locale='sv_SE', group_separator=True) == u'25\xa0123\xa0412\xa0%'
+        assert numbers.format_decimal(29567.12, locale='en_US', group_separator=True) == '29,567.12'
+        assert numbers.format_decimal(29567.12, locale='fr_CA', group_separator=True) == '29\xa0567,12'
+        assert numbers.format_decimal(29567.12, locale='pt_BR', group_separator=True) == '29.567,12'
+        assert numbers.format_currency(1099.98, 'USD', locale='en_US', group_separator=True) == '$1,099.98'
+        assert numbers.format_currency(101299.98, 'EUR', locale='fr_CA', group_separator=True) == '101\xa0299,98\xa0€'
+        assert numbers.format_currency(101299.98, 'EUR', locale='en_US', group_separator=True, format_type='name') == '101,299.98 euros'
+        assert numbers.format_percent(251234.1234, locale='sv_SE', group_separator=True) == '25\xa0123\xa0412\xa0%'
 
     def test_compact(self):
-        assert numbers.format_compact_decimal(1, locale='en_US', format_type="short") == u'1'
-        assert numbers.format_compact_decimal(999, locale='en_US', format_type="short") == u'999'
-        assert numbers.format_compact_decimal(1000, locale='en_US', format_type="short") == u'1K'
-        assert numbers.format_compact_decimal(9000, locale='en_US', format_type="short") == u'9K'
-        assert numbers.format_compact_decimal(9123, locale='en_US', format_type="short", fraction_digits=2) == u'9.12K'
-        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="short") == u'10K'
-        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="short", fraction_digits=2) == u'10K'
-        assert numbers.format_compact_decimal(1000000, locale='en_US', format_type="short") == u'1M'
-        assert numbers.format_compact_decimal(9000999, locale='en_US', format_type="short") == u'9M'
-        assert numbers.format_compact_decimal(9000900099, locale='en_US', format_type="short", fraction_digits=5) == u'9.0009B'
-        assert numbers.format_compact_decimal(1, locale='en_US', format_type="long") == u'1'
-        assert numbers.format_compact_decimal(999, locale='en_US', format_type="long") == u'999'
-        assert numbers.format_compact_decimal(1000, locale='en_US', format_type="long") == u'1 thousand'
-        assert numbers.format_compact_decimal(9000, locale='en_US', format_type="long") == u'9 thousand'
-        assert numbers.format_compact_decimal(9000, locale='en_US', format_type="long", fraction_digits=2) == u'9 thousand'
-        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="long") == u'10 thousand'
-        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="long", fraction_digits=2) == u'10 thousand'
-        assert numbers.format_compact_decimal(1000000, locale='en_US', format_type="long") == u'1 million'
-        assert numbers.format_compact_decimal(9999999, locale='en_US', format_type="long") == u'10 million'
-        assert numbers.format_compact_decimal(9999999999, locale='en_US', format_type="long", fraction_digits=5) == u'10 billion'
-        assert numbers.format_compact_decimal(1, locale='ja_JP', format_type="short") == u'1'
-        assert numbers.format_compact_decimal(999, locale='ja_JP', format_type="short") == u'999'
-        assert numbers.format_compact_decimal(1000, locale='ja_JP', format_type="short") == u'1000'
-        assert numbers.format_compact_decimal(9123, locale='ja_JP', format_type="short") == u'9123'
-        assert numbers.format_compact_decimal(10000, locale='ja_JP', format_type="short") == u'1万'
-        assert numbers.format_compact_decimal(1234567, locale='ja_JP', format_type="long") == u'123万'
-        assert numbers.format_compact_decimal(-1, locale='en_US', format_type="short") == u'-1'
-        assert numbers.format_compact_decimal(-1234, locale='en_US', format_type="short", fraction_digits=2) == u'-1.23K'
-        assert numbers.format_compact_decimal(-123456789, format_type='short', locale='en_US') == u'-123M'
-        assert numbers.format_compact_decimal(-123456789, format_type='long', locale='en_US') == u'-123 million'
-        assert numbers.format_compact_decimal(2345678, locale='mk', format_type='long') == u'2 милиони'
-        assert numbers.format_compact_decimal(21000000, locale='mk', format_type='long') == u'21 милион'
-        assert numbers.format_compact_decimal(21345, locale="gv", format_type="short") == u'21K'
-        assert numbers.format_compact_decimal(1000, locale='it', format_type='long') == u'mille'
-        assert numbers.format_compact_decimal(1234, locale='it', format_type='long') == u'1 mila'
-        assert numbers.format_compact_decimal(1000, locale='fr', format_type='long') == u'mille'
-        assert numbers.format_compact_decimal(1234, locale='fr', format_type='long') == u'1 millier'
+        assert numbers.format_compact_decimal(1, locale='en_US', format_type="short") == '1'
+        assert numbers.format_compact_decimal(999, locale='en_US', format_type="short") == '999'
+        assert numbers.format_compact_decimal(1000, locale='en_US', format_type="short") == '1K'
+        assert numbers.format_compact_decimal(9000, locale='en_US', format_type="short") == '9K'
+        assert numbers.format_compact_decimal(9123, locale='en_US', format_type="short", fraction_digits=2) == '9.12K'
+        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="short") == '10K'
+        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="short", fraction_digits=2) == '10K'
+        assert numbers.format_compact_decimal(1000000, locale='en_US', format_type="short") == '1M'
+        assert numbers.format_compact_decimal(9000999, locale='en_US', format_type="short") == '9M'
+        assert numbers.format_compact_decimal(9000900099, locale='en_US', format_type="short", fraction_digits=5) == '9.0009B'
+        assert numbers.format_compact_decimal(1, locale='en_US', format_type="long") == '1'
+        assert numbers.format_compact_decimal(999, locale='en_US', format_type="long") == '999'
+        assert numbers.format_compact_decimal(1000, locale='en_US', format_type="long") == '1 thousand'
+        assert numbers.format_compact_decimal(9000, locale='en_US', format_type="long") == '9 thousand'
+        assert numbers.format_compact_decimal(9000, locale='en_US', format_type="long", fraction_digits=2) == '9 thousand'
+        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="long") == '10 thousand'
+        assert numbers.format_compact_decimal(10000, locale='en_US', format_type="long", fraction_digits=2) == '10 thousand'
+        assert numbers.format_compact_decimal(1000000, locale='en_US', format_type="long") == '1 million'
+        assert numbers.format_compact_decimal(9999999, locale='en_US', format_type="long") == '10 million'
+        assert numbers.format_compact_decimal(9999999999, locale='en_US', format_type="long", fraction_digits=5) == '10 billion'
+        assert numbers.format_compact_decimal(1, locale='ja_JP', format_type="short") == '1'
+        assert numbers.format_compact_decimal(999, locale='ja_JP', format_type="short") == '999'
+        assert numbers.format_compact_decimal(1000, locale='ja_JP', format_type="short") == '1000'
+        assert numbers.format_compact_decimal(9123, locale='ja_JP', format_type="short") == '9123'
+        assert numbers.format_compact_decimal(10000, locale='ja_JP', format_type="short") == '1万'
+        assert numbers.format_compact_decimal(1234567, locale='ja_JP', format_type="long") == '123万'
+        assert numbers.format_compact_decimal(-1, locale='en_US', format_type="short") == '-1'
+        assert numbers.format_compact_decimal(-1234, locale='en_US', format_type="short", fraction_digits=2) == '-1.23K'
+        assert numbers.format_compact_decimal(-123456789, format_type='short', locale='en_US') == '-123M'
+        assert numbers.format_compact_decimal(-123456789, format_type='long', locale='en_US') == '-123 million'
+        assert numbers.format_compact_decimal(2345678, locale='mk', format_type='long') == '2 милиони'
+        assert numbers.format_compact_decimal(21000000, locale='mk', format_type='long') == '21 милион'
+        assert numbers.format_compact_decimal(21345, locale="gv", format_type="short") == '21K'
+        assert numbers.format_compact_decimal(1000, locale='it', format_type='long') == 'mille'
+        assert numbers.format_compact_decimal(1234, locale='it', format_type='long') == '1 mila'
+        assert numbers.format_compact_decimal(1000, locale='fr', format_type='long') == 'mille'
+        assert numbers.format_compact_decimal(1234, locale='fr', format_type='long') == '1 millier'
+
 
 class NumberParsingTestCase(unittest.TestCase):
 
@@ -224,15 +232,15 @@ def test_validate_currency():
 
 
 def test_is_currency():
-    assert is_currency('EUR') == True
-    assert is_currency('eUr') == False
-    assert is_currency('FUU') == False
-    assert is_currency('') == False
-    assert is_currency(None) == False
-    assert is_currency('   EUR    ') == False
-    assert is_currency('   ') == False
-    assert is_currency([]) == False
-    assert is_currency(set()) == False
+    assert is_currency('EUR')
+    assert not is_currency('eUr')
+    assert not is_currency('FUU')
+    assert not is_currency('')
+    assert not is_currency(None)
+    assert not is_currency('   EUR    ')
+    assert not is_currency('   ')
+    assert not is_currency([])
+    assert not is_currency(set())
 
 
 def test_normalize_currency():
@@ -248,12 +256,12 @@ def test_normalize_currency():
 
 
 def test_get_currency_name():
-    assert numbers.get_currency_name('USD', locale='en_US') == u'US Dollar'
-    assert numbers.get_currency_name('USD', count=2, locale='en_US') == u'US dollars'
+    assert numbers.get_currency_name('USD', locale='en_US') == 'US Dollar'
+    assert numbers.get_currency_name('USD', count=2, locale='en_US') == 'US dollars'
 
 
 def test_get_currency_symbol():
-    assert numbers.get_currency_symbol('USD', 'en_US') == u'$'
+    assert numbers.get_currency_symbol('USD', 'en_US') == '$'
 
 
 def test_get_currency_precision():
@@ -294,24 +302,24 @@ def test_get_territory_currencies():
 
 
 def test_get_decimal_symbol():
-    assert numbers.get_decimal_symbol('en_US') == u'.'
+    assert numbers.get_decimal_symbol('en_US') == '.'
 
 
 def test_get_plus_sign_symbol():
-    assert numbers.get_plus_sign_symbol('en_US') == u'+'
+    assert numbers.get_plus_sign_symbol('en_US') == '+'
 
 
 def test_get_minus_sign_symbol():
-    assert numbers.get_minus_sign_symbol('en_US') == u'-'
-    assert numbers.get_minus_sign_symbol('nl_NL') == u'-'
+    assert numbers.get_minus_sign_symbol('en_US') == '-'
+    assert numbers.get_minus_sign_symbol('nl_NL') == '-'
 
 
 def test_get_exponential_symbol():
-    assert numbers.get_exponential_symbol('en_US') == u'E'
+    assert numbers.get_exponential_symbol('en_US') == 'E'
 
 
 def test_get_group_symbol():
-    assert numbers.get_group_symbol('en_US') == u','
+    assert numbers.get_group_symbol('en_US') == ','
 
 
 def test_decimal_precision():
@@ -321,18 +329,18 @@ def test_decimal_precision():
 
 
 def test_format_decimal():
-    assert numbers.format_decimal(1099, locale='en_US') == u'1,099'
-    assert numbers.format_decimal(1099, locale='de_DE') == u'1.099'
-    assert numbers.format_decimal(1.2345, locale='en_US') == u'1.234'
-    assert numbers.format_decimal(1.2346, locale='en_US') == u'1.235'
-    assert numbers.format_decimal(-1.2346, locale='en_US') == u'-1.235'
-    assert numbers.format_decimal(1.2345, locale='sv_SE') == u'1,234'
-    assert numbers.format_decimal(1.2345, locale='de') == u'1,234'
-    assert numbers.format_decimal(12345.5, locale='en_US') == u'12,345.5'
-    assert numbers.format_decimal(0001.2345000, locale='en_US') == u'1.234'
-    assert numbers.format_decimal(-0001.2346000, locale='en_US') == u'-1.235'
-    assert numbers.format_decimal(0000000.5, locale='en_US') == u'0.5'
-    assert numbers.format_decimal(000, locale='en_US') == u'0'
+    assert numbers.format_decimal(1099, locale='en_US') == '1,099'
+    assert numbers.format_decimal(1099, locale='de_DE') == '1.099'
+    assert numbers.format_decimal(1.2345, locale='en_US') == '1.234'
+    assert numbers.format_decimal(1.2346, locale='en_US') == '1.235'
+    assert numbers.format_decimal(-1.2346, locale='en_US') == '-1.235'
+    assert numbers.format_decimal(1.2345, locale='sv_SE') == '1,234'
+    assert numbers.format_decimal(1.2345, locale='de') == '1,234'
+    assert numbers.format_decimal(12345.5, locale='en_US') == '12,345.5'
+    assert numbers.format_decimal(0001.2345000, locale='en_US') == '1.234'
+    assert numbers.format_decimal(-0001.2346000, locale='en_US') == '-1.235'
+    assert numbers.format_decimal(0000000.5, locale='en_US') == '0.5'
+    assert numbers.format_decimal(000, locale='en_US') == '0'
 
 
 @pytest.mark.parametrize('input_value, expected_value', [
@@ -372,43 +380,43 @@ def test_format_decimal_quantization():
 
 def test_format_currency():
     assert (numbers.format_currency(1099.98, 'USD', locale='en_US')
-            == u'$1,099.98')
+            == '$1,099.98')
     assert (numbers.format_currency(0, 'USD', locale='en_US')
-            == u'$0.00')
+            == '$0.00')
     assert (numbers.format_currency(1099.98, 'USD', locale='es_CO')
-            == u'US$\xa01.099,98')
+            == 'US$\xa01.099,98')
     assert (numbers.format_currency(1099.98, 'EUR', locale='de_DE')
-            == u'1.099,98\xa0\u20ac')
-    assert (numbers.format_currency(1099.98, 'EUR', u'\xa4\xa4 #,##0.00',
+            == '1.099,98\xa0\u20ac')
+    assert (numbers.format_currency(1099.98, 'EUR', '\xa4\xa4 #,##0.00',
                                     locale='en_US')
-            == u'EUR 1,099.98')
+            == 'EUR 1,099.98')
     assert (numbers.format_currency(1099.98, 'EUR', locale='nl_NL')
             != numbers.format_currency(-1099.98, 'EUR', locale='nl_NL'))
     assert (numbers.format_currency(1099.98, 'USD', format=None,
                                     locale='en_US')
-            == u'$1,099.98')
+            == '$1,099.98')
     assert (numbers.format_currency(1, 'USD', locale='es_AR')
-            == u'US$\xa01,00')          # one
+            == 'US$\xa01,00')          # one
     assert (numbers.format_currency(1000000, 'USD', locale='es_AR')
-            == u'US$\xa01.000.000,00')  # many
+            == 'US$\xa01.000.000,00')  # many
     assert (numbers.format_currency(0, 'USD', locale='es_AR')
-            == u'US$\xa00,00')          # other
+            == 'US$\xa00,00')          # other
 
 
 def test_format_currency_format_type():
     assert (numbers.format_currency(1099.98, 'USD', locale='en_US',
                                     format_type="standard")
-            == u'$1,099.98')
+            == '$1,099.98')
     assert (numbers.format_currency(0, 'USD', locale='en_US',
                                     format_type="standard")
-            == u'$0.00')
+            == '$0.00')
 
     assert (numbers.format_currency(1099.98, 'USD', locale='en_US',
                                     format_type="accounting")
-            == u'$1,099.98')
+            == '$1,099.98')
     assert (numbers.format_currency(0, 'USD', locale='en_US',
                                     format_type="accounting")
-            == u'$0.00')
+            == '$0.00')
 
     with pytest.raises(numbers.UnknownCurrencyFormatError) as excinfo:
         numbers.format_currency(1099.98, 'USD', locale='en_US',
@@ -416,27 +424,27 @@ def test_format_currency_format_type():
     assert excinfo.value.args[0] == "'unknown' is not a known currency format type"
 
     assert (numbers.format_currency(1099.98, 'JPY', locale='en_US')
-            == u'\xa51,100')
-    assert (numbers.format_currency(1099.98, 'COP', u'#,##0.00', locale='es_ES')
-            == u'1.099,98')
+            == '\xa51,100')
+    assert (numbers.format_currency(1099.98, 'COP', '#,##0.00', locale='es_ES')
+            == '1.099,98')
     assert (numbers.format_currency(1099.98, 'JPY', locale='en_US',
                                     currency_digits=False)
-            == u'\xa51,099.98')
-    assert (numbers.format_currency(1099.98, 'COP', u'#,##0.00', locale='es_ES',
+            == '\xa51,099.98')
+    assert (numbers.format_currency(1099.98, 'COP', '#,##0.00', locale='es_ES',
                                     currency_digits=False)
-            == u'1.099,98')
+            == '1.099,98')
 
 
 def test_format_compact_currency():
-    assert numbers.format_compact_currency(1, 'USD', locale='en_US', format_type="short") == u'$1'
-    assert numbers.format_compact_currency(999, 'USD', locale='en_US', format_type="short") == u'$999'
-    assert numbers.format_compact_currency(123456789, 'USD', locale='en_US', format_type="short") == u'$123M'
-    assert numbers.format_compact_currency(123456789, 'USD', locale='en_US', fraction_digits=2, format_type="short") == u'$123.46M'
-    assert numbers.format_compact_currency(-123456789, 'USD', locale='en_US', fraction_digits=2, format_type="short") == u'-$123.46M'
-    assert numbers.format_compact_currency(1, 'JPY', locale='ja_JP', format_type="short") == u'￥1'
-    assert numbers.format_compact_currency(1234, 'JPY', locale='ja_JP', format_type="short") == u'￥1234'
-    assert numbers.format_compact_currency(123456, 'JPY', locale='ja_JP', format_type="short") == u'￥12万'
-    assert numbers.format_compact_currency(123456, 'JPY', locale='ja_JP', format_type="short", fraction_digits=2) == u'￥12.35万'
+    assert numbers.format_compact_currency(1, 'USD', locale='en_US', format_type="short") == '$1'
+    assert numbers.format_compact_currency(999, 'USD', locale='en_US', format_type="short") == '$999'
+    assert numbers.format_compact_currency(123456789, 'USD', locale='en_US', format_type="short") == '$123M'
+    assert numbers.format_compact_currency(123456789, 'USD', locale='en_US', fraction_digits=2, format_type="short") == '$123.46M'
+    assert numbers.format_compact_currency(-123456789, 'USD', locale='en_US', fraction_digits=2, format_type="short") == '-$123.46M'
+    assert numbers.format_compact_currency(1, 'JPY', locale='ja_JP', format_type="short") == '￥1'
+    assert numbers.format_compact_currency(1234, 'JPY', locale='ja_JP', format_type="short") == '￥1234'
+    assert numbers.format_compact_currency(123456, 'JPY', locale='ja_JP', format_type="short") == '￥12万'
+    assert numbers.format_compact_currency(123456, 'JPY', locale='ja_JP', format_type="short", fraction_digits=2) == '￥12.35万'
     assert numbers.format_compact_currency(123, 'EUR', locale='yav', format_type="short") == '123\xa0€'
     assert numbers.format_compact_currency(12345, 'EUR', locale='yav', format_type="short") == '12K\xa0€'
     assert numbers.format_compact_currency(123456789, 'EUR', locale='de_DE', fraction_digits=1) == '123,5\xa0Mio.\xa0€'
@@ -444,8 +452,7 @@ def test_format_compact_currency():
 
 def test_format_compact_currency_invalid_format_type():
     with pytest.raises(numbers.UnknownCurrencyFormatError):
-        numbers.format_compact_currency(1099.98, 'USD', locale='en_US',
-                                format_type='unknown')
+        numbers.format_compact_currency(1099.98, 'USD', locale='en_US', format_type='unknown')
 
 
 @pytest.mark.parametrize('input_value, expected_value', [
@@ -485,30 +492,30 @@ def test_format_currency_quantization():
 
 def test_format_currency_long_display_name():
     assert (numbers.format_currency(1099.98, 'USD', locale='en_US', format_type='name')
-            == u'1,099.98 US dollars')
+            == '1,099.98 US dollars')
     assert (numbers.format_currency(1.00, 'USD', locale='en_US', format_type='name')
-            == u'1.00 US dollar')
+            == '1.00 US dollar')
     assert (numbers.format_currency(1.00, 'EUR', locale='en_US', format_type='name')
-            == u'1.00 euro')
+            == '1.00 euro')
     assert (numbers.format_currency(2, 'EUR', locale='en_US', format_type='name')
-            == u'2.00 euros')
+            == '2.00 euros')
     # This tests that '{1} {0}' unitPatterns are found:
     assert (numbers.format_currency(1, 'USD', locale='sw', format_type='name')
-            == u'dola ya Marekani 1.00')
+            == 'dola ya Marekani 1.00')
     # This tests unicode chars:
     assert (numbers.format_currency(1099.98, 'USD', locale='es_GT', format_type='name')
-            == u'dólares estadounidenses 1,099.98')
+            == 'dólares estadounidenses 1,099.98')
     # Test for completely unknown currency, should fallback to currency code
     assert (numbers.format_currency(1099.98, 'XAB', locale='en_US', format_type='name')
-            == u'1,099.98 XAB')
+            == '1,099.98 XAB')
 
     # Test for finding different unit patterns depending on count
     assert (numbers.format_currency(1, 'USD', locale='ro', format_type='name')
-            == u'1,00 dolar american')
+            == '1,00 dolar american')
     assert (numbers.format_currency(2, 'USD', locale='ro', format_type='name')
-            == u'2,00 dolari americani')
+            == '2,00 dolari americani')
     assert (numbers.format_currency(100, 'USD', locale='ro', format_type='name')
-            == u'100,00 de dolari americani')
+            == '100,00 de dolari americani')
 
 
 def test_format_currency_long_display_name_all():
@@ -530,15 +537,15 @@ def test_format_currency_long_display_name_custom_format():
 
 
 def test_format_percent():
-    assert numbers.format_percent(0.34, locale='en_US') == u'34%'
-    assert numbers.format_percent(0, locale='en_US') == u'0%'
-    assert numbers.format_percent(0.34, u'##0%', locale='en_US') == u'34%'
-    assert numbers.format_percent(34, u'##0', locale='en_US') == u'34'
-    assert numbers.format_percent(25.1234, locale='en_US') == u'2,512%'
+    assert numbers.format_percent(0.34, locale='en_US') == '34%'
+    assert numbers.format_percent(0, locale='en_US') == '0%'
+    assert numbers.format_percent(0.34, '##0%', locale='en_US') == '34%'
+    assert numbers.format_percent(34, '##0', locale='en_US') == '34'
+    assert numbers.format_percent(25.1234, locale='en_US') == '2,512%'
     assert (numbers.format_percent(25.1234, locale='sv_SE')
-            == u'2\xa0512\xa0%')
-    assert (numbers.format_percent(25.1234, u'#,##0\u2030', locale='en_US')
-            == u'25,123\u2030')
+            == '2\xa0512\xa0%')
+    assert (numbers.format_percent(25.1234, '#,##0\u2030', locale='en_US')
+            == '25,123\u2030')
 
 
 @pytest.mark.parametrize('input_value, expected_value', [
@@ -576,25 +583,25 @@ def test_format_percent_quantization():
 
 
 def test_format_scientific():
-    assert numbers.format_scientific(10000, locale='en_US') == u'1E4'
-    assert numbers.format_scientific(4234567, u'#.#E0', locale='en_US') == u'4.2E6'
-    assert numbers.format_scientific(4234567, u'0E0000', locale='en_US') == u'4.234567E0006'
-    assert numbers.format_scientific(4234567, u'##0E00', locale='en_US') == u'4.234567E06'
-    assert numbers.format_scientific(4234567, u'##00E00', locale='en_US') == u'42.34567E05'
-    assert numbers.format_scientific(4234567, u'0,000E00', locale='en_US') == u'4,234.567E03'
-    assert numbers.format_scientific(4234567, u'##0.#####E00', locale='en_US') == u'4.23457E06'
-    assert numbers.format_scientific(4234567, u'##0.##E00', locale='en_US') == u'4.23E06'
-    assert numbers.format_scientific(42, u'00000.000000E0000', locale='en_US') == u'42000.000000E-0003'
+    assert numbers.format_scientific(10000, locale='en_US') == '1E4'
+    assert numbers.format_scientific(4234567, '#.#E0', locale='en_US') == '4.2E6'
+    assert numbers.format_scientific(4234567, '0E0000', locale='en_US') == '4.234567E0006'
+    assert numbers.format_scientific(4234567, '##0E00', locale='en_US') == '4.234567E06'
+    assert numbers.format_scientific(4234567, '##00E00', locale='en_US') == '42.34567E05'
+    assert numbers.format_scientific(4234567, '0,000E00', locale='en_US') == '4,234.567E03'
+    assert numbers.format_scientific(4234567, '##0.#####E00', locale='en_US') == '4.23457E06'
+    assert numbers.format_scientific(4234567, '##0.##E00', locale='en_US') == '4.23E06'
+    assert numbers.format_scientific(42, '00000.000000E0000', locale='en_US') == '42000.000000E-0003'
 
 
 def test_default_scientific_format():
     """ Check the scientific format method auto-correct the rendering pattern
     in case of a missing fractional part.
     """
-    assert numbers.format_scientific(12345, locale='en_US') == u'1.2345E4'
-    assert numbers.format_scientific(12345.678, locale='en_US') == u'1.2345678E4'
-    assert numbers.format_scientific(12345, u'#E0', locale='en_US') == u'1.2345E4'
-    assert numbers.format_scientific(12345.678, u'#E0', locale='en_US') == u'1.2345678E4'
+    assert numbers.format_scientific(12345, locale='en_US') == '1.2345E4'
+    assert numbers.format_scientific(12345.678, locale='en_US') == '1.2345678E4'
+    assert numbers.format_scientific(12345, '#E0', locale='en_US') == '1.2345E4'
+    assert numbers.format_scientific(12345.678, '#E0', locale='en_US') == '1.2345678E4'
 
 
 @pytest.mark.parametrize('input_value, expected_value', [
@@ -660,18 +667,18 @@ def test_parse_grouping():
 def test_parse_pattern():
 
     # Original pattern is preserved
-    np = numbers.parse_pattern(u'¤#,##0.00')
-    assert np.pattern == u'¤#,##0.00'
+    np = numbers.parse_pattern('¤#,##0.00')
+    assert np.pattern == '¤#,##0.00'
 
-    np = numbers.parse_pattern(u'¤#,##0.00;(¤#,##0.00)')
-    assert np.pattern == u'¤#,##0.00;(¤#,##0.00)'
+    np = numbers.parse_pattern('¤#,##0.00;(¤#,##0.00)')
+    assert np.pattern == '¤#,##0.00;(¤#,##0.00)'
 
     # Given a NumberPattern object, we don't return a new instance.
     # However, we don't cache NumberPattern objects, so calling
     # parse_pattern with the same format string will create new
     # instances
-    np1 = numbers.parse_pattern(u'¤ #,##0.00')
-    np2 = numbers.parse_pattern(u'¤ #,##0.00')
+    np1 = numbers.parse_pattern('¤ #,##0.00')
+    np2 = numbers.parse_pattern('¤ #,##0.00')
     assert np1 is not np2
     assert np1 is numbers.parse_pattern(np1)
 
@@ -679,19 +686,19 @@ def test_parse_pattern():
 def test_parse_pattern_negative():
 
     # No negative format specified
-    np = numbers.parse_pattern(u'¤#,##0.00')
-    assert np.prefix == (u'¤', u'-¤')
-    assert np.suffix == (u'', u'')
+    np = numbers.parse_pattern('¤#,##0.00')
+    assert np.prefix == ('¤', '-¤')
+    assert np.suffix == ('', '')
 
     # Negative format is specified
-    np = numbers.parse_pattern(u'¤#,##0.00;(¤#,##0.00)')
-    assert np.prefix == (u'¤', u'(¤')
-    assert np.suffix == (u'', u')')
+    np = numbers.parse_pattern('¤#,##0.00;(¤#,##0.00)')
+    assert np.prefix == ('¤', '(¤')
+    assert np.suffix == ('', ')')
 
     # Negative sign is a suffix
-    np = numbers.parse_pattern(u'¤ #,##0.00;¤ #,##0.00-')
-    assert np.prefix == (u'¤ ', u'¤ ')
-    assert np.suffix == (u'', u'-')
+    np = numbers.parse_pattern('¤ #,##0.00;¤ #,##0.00-')
+    assert np.prefix == ('¤ ', '¤ ')
+    assert np.suffix == ('', '-')
 
 
 def test_numberpattern_repr():
@@ -699,7 +706,7 @@ def test_numberpattern_repr():
 
     # This implementation looks a bit funny, but that's cause strings are
     # repr'd differently in Python 2 vs 3 and this test runs under both.
-    format = u'¤#,##0.00;(¤#,##0.00)'
+    format = '¤#,##0.00;(¤#,##0.00)'
     np = numbers.parse_pattern(format)
     assert repr(format) in repr(np)
 
diff --git a/tests/test_plural.py b/tests/test_plural.py
index 16601cf..e1e5ead 100644
--- a/tests/test_plural.py
+++ b/tests/test_plural.py
@@ -11,9 +11,10 @@
 # history and logs, available at http://babel.edgewall.org/log/.
 import decimal
 import unittest
+
 import pytest
 
-from babel import plural, localedata
+from babel import localedata, plural
 
 EPSILON = decimal.Decimal("0.0001")
 
diff --git a/tests/test_smoke.py b/tests/test_smoke.py
index aed676a..c916845 100644
--- a/tests/test_smoke.py
+++ b/tests/test_smoke.py
@@ -4,11 +4,12 @@ looking at improving test coverage.  They just verify that basic
 operations don't fail due to odd corner cases on any locale that
 we ship.
 """
-import decimal
 import datetime
+import decimal
+
 import pytest
 
-from babel import Locale, units, dates, numbers
+from babel import Locale, dates, numbers, units
 
 NUMBERS = (
     decimal.Decimal("-33.76"),  # Negative Decimal
diff --git a/tests/test_support.py b/tests/test_support.py
index 3ca0be3..0b7cba0 100644
--- a/tests/test_support.py
+++ b/tests/test_support.py
@@ -13,20 +13,21 @@
 import inspect
 import os
 import shutil
+import sys
 import tempfile
 import unittest
-import pytest
-import sys
 from datetime import date, datetime, timedelta
 from io import BytesIO
 
+import pytest
+
 from babel import support
 from babel.messages import Catalog
 from babel.messages.mofile import write_mo
 
-
 SKIP_LGETTEXT = sys.version_info >= (3, 8)
 
+
 @pytest.mark.usefixtures("os_environ")
 class TranslationsTestCase(unittest.TestCase):
 
@@ -71,9 +72,9 @@ class TranslationsTestCase(unittest.TestCase):
                                                                      'foo'))
 
     def test_upgettext(self):
-        self.assertEqualTypeToo(u'Voh', self.translations.ugettext('foo'))
-        self.assertEqualTypeToo(u'VohCTX', self.translations.upgettext('foo',
-                                                                       'foo'))
+        self.assertEqualTypeToo('Voh', self.translations.ugettext('foo'))
+        self.assertEqualTypeToo('VohCTX', self.translations.upgettext('foo',
+                                                                      'foo'))
 
     @pytest.mark.skipif(SKIP_LGETTEXT, reason="lgettext is deprecated")
     def test_lpgettext(self):
@@ -94,14 +95,14 @@ class TranslationsTestCase(unittest.TestCase):
                                                             'foos1', 2))
 
     def test_unpgettext(self):
-        self.assertEqualTypeToo(u'Voh1',
+        self.assertEqualTypeToo('Voh1',
                                 self.translations.ungettext('foo1', 'foos1', 1))
-        self.assertEqualTypeToo(u'Vohs1',
+        self.assertEqualTypeToo('Vohs1',
                                 self.translations.ungettext('foo1', 'foos1', 2))
-        self.assertEqualTypeToo(u'VohCTX1',
+        self.assertEqualTypeToo('VohCTX1',
                                 self.translations.unpgettext('foo', 'foo1',
                                                              'foos1', 1))
-        self.assertEqualTypeToo(u'VohsCTX1',
+        self.assertEqualTypeToo('VohsCTX1',
                                 self.translations.unpgettext('foo', 'foo1',
                                                              'foos1', 2))
 
@@ -126,9 +127,9 @@ class TranslationsTestCase(unittest.TestCase):
 
     def test_dupgettext(self):
         self.assertEqualTypeToo(
-            u'VohD', self.translations.dugettext('messages1', 'foo'))
+            'VohD', self.translations.dugettext('messages1', 'foo'))
         self.assertEqualTypeToo(
-            u'VohCTXD', self.translations.dupgettext('messages1', 'foo', 'foo'))
+            'VohCTXD', self.translations.dupgettext('messages1', 'foo', 'foo'))
 
     @pytest.mark.skipif(SKIP_LGETTEXT, reason="lgettext is deprecated")
     def test_ldpgettext(self):
@@ -151,15 +152,15 @@ class TranslationsTestCase(unittest.TestCase):
 
     def test_dunpgettext(self):
         self.assertEqualTypeToo(
-            u'VohD1', self.translations.dungettext('messages1', 'foo1', 'foos1', 1))
+            'VohD1', self.translations.dungettext('messages1', 'foo1', 'foos1', 1))
         self.assertEqualTypeToo(
-            u'VohsD1', self.translations.dungettext('messages1', 'foo1', 'foos1', 2))
+            'VohsD1', self.translations.dungettext('messages1', 'foo1', 'foos1', 2))
         self.assertEqualTypeToo(
-            u'VohCTXD1', self.translations.dunpgettext('messages1', 'foo', 'foo1',
-                                                       'foos1', 1))
+            'VohCTXD1', self.translations.dunpgettext('messages1', 'foo', 'foo1',
+                                                      'foos1', 1))
         self.assertEqualTypeToo(
-            u'VohsCTXD1', self.translations.dunpgettext('messages1', 'foo', 'foo1',
-                                                        'foos1', 2))
+            'VohsCTXD1', self.translations.dunpgettext('messages1', 'foo', 'foo1',
+                                                       'foos1', 2))
 
     @pytest.mark.skipif(SKIP_LGETTEXT, reason="lgettext is deprecated")
     def test_ldnpgettext(self):
@@ -219,9 +220,9 @@ class NullTranslationsTestCase(unittest.TestCase):
 
     def test_same_return_values(self):
         data = {
-            'message': u'foo', 'domain': u'domain', 'context': 'tests',
-            'singular': u'bar', 'plural': u'baz', 'num': 1,
-            'msgid1': u'bar', 'msgid2': u'baz', 'n': 1,
+            'message': 'foo', 'domain': 'domain', 'context': 'tests',
+            'singular': 'bar', 'plural': 'baz', 'num': 1,
+            'msgid1': 'bar', 'msgid2': 'baz', 'n': 1,
         }
         for name in self.method_names():
             method = getattr(self.translations, name)
@@ -346,21 +347,20 @@ def test_lazy_proxy():
         return f"Hello, {name}!"
 
     lazy_greeting = support.LazyProxy(greeting, name='Joe')
-    assert str(lazy_greeting) == u"Hello, Joe!"
-    assert u'  ' + lazy_greeting == u'  Hello, Joe!'
-    assert u'(%s)' % lazy_greeting == u'(Hello, Joe!)'
+    assert str(lazy_greeting) == "Hello, Joe!"
+    assert '  ' + lazy_greeting == '  Hello, Joe!'
+    assert '(%s)' % lazy_greeting == '(Hello, Joe!)'
     assert f"[{lazy_greeting}]" == "[Hello, Joe!]"
 
-    greetings = [
+    greetings = sorted([
         support.LazyProxy(greeting, 'world'),
         support.LazyProxy(greeting, 'Joe'),
         support.LazyProxy(greeting, 'universe'),
-    ]
-    greetings.sort()
+    ])
     assert [str(g) for g in greetings] == [
-        u"Hello, Joe!",
-        u"Hello, universe!",
-        u"Hello, world!",
+        "Hello, Joe!",
+        "Hello, universe!",
+        "Hello, world!",
     ]
 
 
diff --git a/tests/test_util.py b/tests/test_util.py
index d78aee7..ae861dd 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -11,6 +11,7 @@
 # history and logs, available at http://babel.edgewall.org/log/.
 
 import __future__
+
 import unittest
 from io import BytesIO
 
@@ -21,11 +22,12 @@ from babel.util import parse_future_flags
 
 
 class _FF:
-    division         = __future__.division.compiler_flag
-    print_function   = __future__.print_function.compiler_flag
-    with_statement   = __future__.with_statement.compiler_flag
+    division = __future__.division.compiler_flag
+    print_function = __future__.print_function.compiler_flag
+    with_statement = __future__.with_statement.compiler_flag
     unicode_literals = __future__.unicode_literals.compiler_flag
 
+
 def test_distinct():
     assert list(util.distinct([1, 2, 1, 3, 4, 4])) == [1, 2, 3, 4]
     assert list(util.distinct('foobar')) == ['f', 'o', 'b', 'a', 'r']
@@ -47,7 +49,7 @@ def test_pathmatch():
 class FixedOffsetTimezoneTestCase(unittest.TestCase):
 
     def test_zone_negative_offset(self):
-        assert util.FixedOffsetTimezone((-60)).zone == 'Etc/GMT-60'
+        assert util.FixedOffsetTimezone(-60).zone == 'Etc/GMT-60'
 
     def test_zone_zero_offset(self):
         assert util.FixedOffsetTimezone(0).zone == 'Etc/GMT+0'
@@ -56,19 +58,20 @@ class FixedOffsetTimezoneTestCase(unittest.TestCase):
         assert util.FixedOffsetTimezone(330).zone == 'Etc/GMT+330'
 
 
-parse_encoding = lambda s: util.parse_encoding(BytesIO(s.encode('utf-8')))
+def parse_encoding(s):
+    return util.parse_encoding(BytesIO(s.encode('utf-8')))
 
 
 def test_parse_encoding_defined():
-    assert parse_encoding(u'# coding: utf-8') == 'utf-8'
+    assert parse_encoding('# coding: utf-8') == 'utf-8'
 
 
 def test_parse_encoding_undefined():
-    assert parse_encoding(u'') is None
+    assert parse_encoding('') is None
 
 
 def test_parse_encoding_non_ascii():
-    assert parse_encoding(u'K\xf6ln') is None
+    assert parse_encoding('K\xf6ln') is None
 
 
 @pytest.mark.parametrize('source, result', [