Remove Python 2 compatibility (#1348)

* Remove Python 2 compatibility

* remove 2/3 shims in pygments.util
* update setup.py metadata

* Remove unneeded object inheritance.

* Remove unneeded future imports.

1 files changed, 15 insertions, 52 deletions

diff --git a/pygments/util.py b/pygments/util.py
index 59669d2b..92e4f259 100644
--- a/pygments/util.py
+++ b/pygments/util.py
@@ -11,6 +11,7 @@
 
 import re
 import sys
+from io import TextIOWrapper
 
 
 split_path_re = re.compile(r'[/\\ ]')
@@ -53,7 +54,7 @@ def get_bool_opt(options, optname, default=None):
         return string
     elif isinstance(string, int):
         return bool(string)
-    elif not isinstance(string, string_types):
+    elif not isinstance(string, str):
         raise OptionError('Invalid type %r for option %s; use '
                           '1/0, yes/no, true/false, on/off' % (
                               string, optname))
@@ -83,7 +84,7 @@ def get_int_opt(options, optname, default=None):
 
 def get_list_opt(options, optname, default=None):
     val = options.get(optname, default)
-    if isinstance(val, string_types):
+    if isinstance(val, str):
         return val.split()
     elif isinstance(val, (list, tuple)):
         return list(val)
@@ -224,7 +225,7 @@ def unirange(a, b):
 
     if sys.maxunicode > 0xffff:
         # wide build
-        return u'[%s-%s]' % (unichr(a), unichr(b))
+        return u'[%s-%s]' % (chr(a), chr(b))
     else:
         # narrow build stores surrogates, and the 're' module handles them
         # (incorrectly) as characters.  Since there is still ordering among
@@ -232,24 +233,23 @@ def unirange(a, b):
         # background in http://bugs.python.org/issue3665 and
         # http://bugs.python.org/issue12749
         #
-        # Additionally, the lower constants are using unichr rather than
+        # Additionally, the lower constants are using chr rather than
         # literals because jython [which uses the wide path] can't load this
         # file if they are literals.
         ah, al = _surrogatepair(a)
         bh, bl = _surrogatepair(b)
         if ah == bh:
-            return u'(?:%s[%s-%s])' % (unichr(ah), unichr(al), unichr(bl))
+            return u'(?:%s[%s-%s])' % (chr(ah), chr(al), chr(bl))
         else:
             buf = []
-            buf.append(u'%s[%s-%s]' %
-                       (unichr(ah), unichr(al),
-                        ah == bh and unichr(bl) or unichr(0xdfff)))
+            buf.append(u'%s[%s-%s]' % (chr(ah), chr(al),
+                                       ah == bh and chr(bl) or chr(0xdfff)))
             if ah - bh > 1:
                 buf.append(u'[%s-%s][%s-%s]' %
-                           unichr(ah+1), unichr(bh-1), unichr(0xdc00), unichr(0xdfff))
+                           chr(ah+1), chr(bh-1), chr(0xdc00), chr(0xdfff))
             if ah != bh:
                 buf.append(u'%s[%s-%s]' %
-                           (unichr(bh), unichr(0xdc00), unichr(bl)))
+                           (chr(bh), chr(0xdc00), chr(bl)))
 
             return u'(?:' + u'|'.join(buf) + u')'
 
@@ -289,7 +289,7 @@ def duplicates_removed(it, already_seen=()):
     return lst
 
 
-class Future(object):
+class Future:
     """Generic class to defer some work.
 
     Handled specially in RegexLexerMeta, to support regex string construction at
@@ -345,44 +345,7 @@ def terminal_encoding(term):
     return locale.getpreferredencoding()
 
 
-# Python 2/3 compatibility
-
-if sys.version_info < (3, 0):
-    unichr = unichr
-    xrange = xrange
-    string_types = (str, unicode)
-    text_type = unicode
-    u_prefix = 'u'
-    iteritems = dict.iteritems
-    itervalues = dict.itervalues
-    import StringIO
-    import cStringIO
-    # unfortunately, io.StringIO in Python 2 doesn't accept str at all
-    StringIO = StringIO.StringIO
-    BytesIO = cStringIO.StringIO
-else:
-    unichr = chr
-    xrange = range
-    string_types = (str,)
-    text_type = str
-    u_prefix = ''
-    iteritems = dict.items
-    itervalues = dict.values
-    from io import StringIO, BytesIO, TextIOWrapper
-
-    class UnclosingTextIOWrapper(TextIOWrapper):
-        # Don't close underlying buffer on destruction.
-        def close(self):
-            self.flush()
-
-
-def add_metaclass(metaclass):
-    """Class decorator for creating a class with a metaclass."""
-    def wrapper(cls):
-        orig_vars = cls.__dict__.copy()
-        orig_vars.pop('__dict__', None)
-        orig_vars.pop('__weakref__', None)
-        for slots_var in orig_vars.get('__slots__', ()):
-            orig_vars.pop(slots_var)
-        return metaclass(cls.__name__, cls.__bases__, orig_vars)
-    return wrapper
+class UnclosingTextIOWrapper(TextIOWrapper):
+    # Don't close underlying buffer on destruction.
+    def close(self):
+        self.flush()