Resolve flake8 errors in non-test code.

11 files changed, 35 insertions, 14 deletions

diff --git a/natsort/__init__.py b/natsort/__init__.py
index 9980418..830f8ab 100644
--- a/natsort/__init__.py
+++ b/natsort/__init__.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import print_function, division, unicode_literals, absolute_import
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 import sys
 
diff --git a/natsort/compat/fake_fastnumbers.py b/natsort/compat/fake_fastnumbers.py
index c4b8ada..27ce027 100644
--- a/natsort/compat/fake_fastnumbers.py
+++ b/natsort/compat/fake_fastnumbers.py
@@ -37,6 +37,7 @@ NAN_INF = [
 NAN_INF.extend(["+" + x[:2] for x in NAN_INF] + ["-" + x[:2] for x in NAN_INF])
 NAN_INF = frozenset(NAN_INF)
 ASCII_NUMS = "0123456789+-"
+POTENTIAL_FIRST_CHAR = frozenset(decimal_chars + list(ASCII_NUMS + "."))
 
 
 # noinspection PyIncorrectDocstring
@@ -46,7 +47,7 @@ def fast_float(
     nan=None,
     _uni=unicodedata.numeric,
     _nan_inf=NAN_INF,
-    _first_char=frozenset(decimal_chars + list(ASCII_NUMS + ".")),
+    _first_char=POTENTIAL_FIRST_CHAR,
 ):
     """
     Convert a string to a float quickly, return input as-is if not possible.
@@ -89,7 +90,7 @@ def fast_int(
     x,
     key=lambda x: x,
     _uni=unicodedata.digit,
-    _first_char=frozenset(decimal_chars + list(ASCII_NUMS)),
+    _first_char=POTENTIAL_FIRST_CHAR,
 ):
     """
     Convert a string to a int quickly, return input as-is if not possible.
diff --git a/natsort/compat/fastnumbers.py b/natsort/compat/fastnumbers.py
index 0141387..b1468b3 100644
--- a/natsort/compat/fastnumbers.py
+++ b/natsort/compat/fastnumbers.py
@@ -3,7 +3,7 @@
 Interface for natsort to access fastnumbers functions without
 having to worry if it is actually installed.
 """
-from __future__ import print_function, division, unicode_literals, absolute_import
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 from distutils.version import StrictVersion
 
@@ -17,4 +17,4 @@ try:
     if StrictVersion(fn_ver) < StrictVersion("2.0.0"):
         raise ImportError  # pragma: no cover
 except ImportError:
-    from natsort.compat.fake_fastnumbers import fast_float, fast_int
+    from natsort.compat.fake_fastnumbers import fast_float, fast_int  # noqa: F401
diff --git a/natsort/compat/locale.py b/natsort/compat/locale.py
index 45f5bc4..1629ba0 100644
--- a/natsort/compat/locale.py
+++ b/natsort/compat/locale.py
@@ -3,7 +3,7 @@
 Interface for natsort to access locale functionality without
 having to worry about if it is using PyICU or the built-in locale.
 """
-from __future__ import print_function, division, unicode_literals, absolute_import
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 # Std. lib imports.
 import sys
@@ -20,7 +20,7 @@ null_string_max = py23_unichr(sys.maxunicode) * 20
 # Make the strxfrm function from strcoll on Python2
 # It can be buggy (especially on BSD-based systems),
 # so prefer icu if available.
-try:
+try:  # noqa: C901
     import icu
     from locale import getlocale
 
diff --git a/natsort/compat/pathlib.py b/natsort/compat/pathlib.py
index e95e847..a189f37 100644
--- a/natsort/compat/pathlib.py
+++ b/natsort/compat/pathlib.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import print_function, division, unicode_literals, absolute_import
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 try:
     from pathlib import PurePath  # PurePath is the base object for Paths.
diff --git a/natsort/natsort.py b/natsort/natsort.py
index 3be3a37..27f532d 100644
--- a/natsort/natsort.py
+++ b/natsort/natsort.py
@@ -640,7 +640,7 @@ def order_by_index(seq, index, iter=False):
 if float(sys.version[:3]) < 3:
     # pylint: disable=unused-variable
     # noinspection PyUnresolvedReferences,PyPep8Naming
-    class natcmp(object):
+    class natcmp(object):  # noqa: N801
         """
         Compare two objects using a key and an algorithm.
 
diff --git a/natsort/ns_enum.py b/natsort/ns_enum.py
index fee7cc4..be61295 100644
--- a/natsort/ns_enum.py
+++ b/natsort/ns_enum.py
@@ -3,7 +3,7 @@
 This module defines the "ns" enum for natsort is used to determine
 what algorithm natsort uses.
 """
-from __future__ import print_function, division, unicode_literals, absolute_import
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 import collections
 
diff --git a/natsort/unicode_numbers.py b/natsort/unicode_numbers.py
index 8832a1c..28cbafc 100644
--- a/natsort/unicode_numbers.py
+++ b/natsort/unicode_numbers.py
@@ -2,7 +2,7 @@
 """
 Pre-determine the collection of unicode decimals, digits, and numerals.
 """
-from __future__ import division, print_function, absolute_import, unicode_literals
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 import unicodedata
 
diff --git a/natsort/utils.py b/natsort/utils.py
index ec0c1b0..496904a 100644
--- a/natsort/utils.py
+++ b/natsort/utils.py
@@ -637,9 +637,12 @@ def final_data_transform_factory(alg, sep, pre_sep):
         return lambda split_val, val: tuple(split_val)
 
 
+lower_function = methodcaller("casefold" if NEWPY else "lower")
+
+
 # noinspection PyIncorrectDocstring
 @u_format
-def groupletters(x, _low=methodcaller("casefold" if NEWPY else "lower")):
+def groupletters(x, _low=lower_function):
     """
     Double all characters, making doubled letters lowercase.
 
diff --git a/setup.cfg b/setup.cfg
index fbcd8dd..13b832e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -50,4 +50,21 @@ search = XX-XX-XXXX v. X.X.X
 replace = {now:%%m-%%d-%%Y} v. {new_version}
 
 [flake8]
-max-line-length = 90
+max-line-length = 89
+import-order-style = pycharm
+doctests = True
+max-complexity = 10
+exclude =
+    natsort.egg-info,
+    .tox,
+    .cache,
+    .git,
+    __pycache__,
+    build,
+    dist,
+    # This has mostly auto-generated code
+    docs,
+    # Let's not check library code
+    .venv,
+    # This file simply has too many intentional errors
+    natsort/compat/py23.py
\ No newline at end of file
diff --git a/setup.py b/setup.py
index ad538ee..e93dd3a 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 #! /usr/bin/env python
 
-from setuptools import setup, find_packages
+from setuptools import find_packages, setup
 setup(
     name='natsort',
     version='5.4.0',