Revert "Revert "Drop support for EOL Pythons""

This reverts commit 916a92d39eaf5ef282b421c4772a7ec831750c4c.

16 files changed, 76 insertions, 85 deletions

diff --git a/README.rst b/README.rst
index dd4d4b8..c495f57 100644
--- a/README.rst
+++ b/README.rst
@@ -329,8 +329,7 @@ from the command line with ``python -m natsort``.
 Requirements
 ------------
 
-``natsort`` requires Python version 2.6 or greater or Python 3.3 or greater.
-It may run on (but is not tested against) Python 3.2.
+``natsort`` requires Python version 2.7 or Python 3.4 or greater.
 
 Optional Dependencies
 ---------------------
diff --git a/docs/examples.rst b/docs/examples.rst
index 4a0040b..f49100d 100644
--- a/docs/examples.rst
+++ b/docs/examples.rst
@@ -240,7 +240,7 @@ sort key so that:
     ...    def __init__(self, bar):
     ...        self.bar = bar
     ...    def __repr__(self):
-    ...        return "Foo('{0}')".format(self.bar)
+    ...        return "Foo('{}')".format(self.bar)
     >>> b = [Foo('num3'), Foo('num5'), Foo('num2')]
     >>> natsorted(b, key=attrgetter('bar'))
     [Foo('num2'), Foo('num3'), Foo('num5')]
diff --git a/docs/howitworks.rst b/docs/howitworks.rst
index fff6439..3ecb406 100644
--- a/docs/howitworks.rst
+++ b/docs/howitworks.rst
@@ -897,10 +897,7 @@ It turns out the there is a bug in the legacy Python implementation of
 input (https://bugs.python.org/issue2481). :func:`locale.strcoll` works,
 but is intended for use with ``cmp``, which does not exist in current Python
 implementations. Luckily, the :func:`functools.cmp_to_key` function
-makes :func:`locale.strcoll` behave like :func:`locale.strxfrm` (that is, of course,
-unless you are on Python 2.6 where :func:`functools.cmp_to_key` doesn't exist,
-in which case you simply copy-paste the implementation from Python 2.7
-directly into your code ☹).
+makes :func:`locale.strcoll` behave like :func:`locale.strxfrm`.
 
 Handling Broken Locale On OSX
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/docs/intro.rst b/docs/intro.rst
index 4bab725..8f9dba2 100644
--- a/docs/intro.rst
+++ b/docs/intro.rst
@@ -324,8 +324,7 @@ from the command line with ``python -m natsort``.
 Requirements
 ------------
 
-:mod:`natsort` requires Python version 2.6 or greater or Python 3.3 or greater.
-It may run on (but is not tested against) Python 3.2.
+:mod:`natsort` requires Python version 2.7 or Python 3.4 or greater.
 
 Optional Dependencies
 ---------------------
diff --git a/natsort/__init__.py b/natsort/__init__.py
index 00e2205..787da5f 100644
--- a/natsort/__init__.py
+++ b/natsort/__init__.py
@@ -54,4 +54,4 @@ __all__ = [
 # them to natsort's main namespace.
 with warnings.catch_warnings():
     warnings.simplefilter("ignore")
-    globals().update(dict((k, getattr(ns, k)) for k in dir(ns) if k.isupper()))
+    globals().update(ns._asdict())
diff --git a/natsort/__main__.py b/natsort/__main__.py
index c06c9b8..70d9572 100644
--- a/natsort/__main__.py
+++ b/natsort/__main__.py
@@ -24,7 +24,7 @@ def main(*arguments):
     parser.add_argument(
         "--version",
         action="version",
-        version="%(prog)s {0}".format(natsort.__version__),
+        version="%(prog)s {}".format(natsort.__version__),
     )
     parser.add_argument(
         "-p",
diff --git a/natsort/compat/locale.py b/natsort/compat/locale.py
index 1629ba0..41abea6 100644
--- a/natsort/compat/locale.py
+++ b/natsort/compat/locale.py
@@ -7,9 +7,10 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 
 # Std. lib imports.
 import sys
+from functools import cmp_to_key
 
 # Local imports.
-from natsort.compat.py23 import PY_VERSION, cmp_to_key, py23_unichr
+from natsort.compat.py23 import PY_VERSION, py23_unichr
 
 # This string should be sorted after any other byte string because
 # it contains the max unicode character repeated 20 times.
diff --git a/natsort/compat/py23.py b/natsort/compat/py23.py
index ba9abd9..58f7487 100644
--- a/natsort/compat/py23.py
+++ b/natsort/compat/py23.py
@@ -56,43 +56,6 @@ else:
     py23_map = itertools.imap
     py23_filter = itertools.ifilter
 
-# cmp_to_key was not created till 2.7, so require this for 2.6
-try:
-    from functools import cmp_to_key
-except ImportError:  # pragma: no cover
-
-    def cmp_to_key(mycmp):
-        """Convert a cmp= function into a key= function"""
-
-        class K(object):
-            __slots__ = ["obj"]
-
-            def __init__(self, obj):
-                self.obj = obj
-
-            def __lt__(self, other):
-                return mycmp(self.obj, other.obj) < 0
-
-            def __gt__(self, other):
-                return mycmp(self.obj, other.obj) > 0
-
-            def __eq__(self, other):
-                return mycmp(self.obj, other.obj) == 0
-
-            def __le__(self, other):
-                return mycmp(self.obj, other.obj) <= 0
-
-            def __ge__(self, other):
-                return mycmp(self.obj, other.obj) >= 0
-
-            def __ne__(self, other):
-                return mycmp(self.obj, other.obj) != 0
-
-            def __hash__(self):
-                raise TypeError("hash not implemented")
-
-        return K
-
 
 # This function is intended to decorate other functions that will modify
 # either a string directly, or a function's docstring.
diff --git a/natsort/natsort.py b/natsort/natsort.py
index 47cc9f1..ad4f0d9 100644
--- a/natsort/natsort.py
+++ b/natsort/natsort.py
@@ -160,7 +160,7 @@ def natsort_keygen(key=None, alg=ns.DEFAULT, **_kwargs):
         alg = utils.args_to_enum(**_kwargs) | alg
     except TypeError:
         msg = "natsort_keygen: 'alg' argument must be from the enum 'ns'"
-        raise ValueError(msg + ", got {0}".format(py23_str(alg)))
+        raise ValueError(msg + ", got {}".format(py23_str(alg)))
 
     # Add the _DUMB option if the locale library is broken.
     if alg & ns.LOCALEALPHA and natsort.compat.locale.dumb_sort():
@@ -687,7 +687,7 @@ if float(sys.version[:3]) < 3:
                 alg = utils.args_to_enum(**kwargs) | alg
             except TypeError:
                 msg = "natsort_keygen: 'alg' argument must be " "from the enum 'ns'"
-                raise ValueError(msg + ", got {0}".format(py23_str(alg)))
+                raise ValueError(msg + ", got {}".format(py23_str(alg)))
 
             # Add the _DUMB option if the locale library is broken.
             if alg & ns.LOCALEALPHA and natsort.compat.locale.dumb_sort():
diff --git a/natsort/ns_enum.py b/natsort/ns_enum.py
index 29f8d87..c79884b 100644
--- a/natsort/ns_enum.py
+++ b/natsort/ns_enum.py
@@ -8,8 +8,6 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 import collections
 import warnings
 
-# NOTE: OrderedDict is not used below for compatibility with Python 2.6.
-
 # The below are the base ns options. The values will be stored as powers
 # of two so bitmasks can be used to extract the user's requested options.
 enum_options = [
@@ -58,26 +56,25 @@ enum_aliases = [
 ]
 
 # Construct the list of bitwise distinct enums with their fields.
-enum_fields = [(name, 1 << i) for i, name in enumerate(enum_options)]
-enum_fields.extend((name, 0) for name in enum_do_nothing)
+enum_fields = collections.OrderedDict(
+    (name, 1 << i) for i, name in enumerate(enum_options)
+)
+enum_fields.update((name, 0) for name in enum_do_nothing)
 
 for name, combo in enum_combos:
-    current_mapping = dict(enum_fields)
-    combined_value = current_mapping[combo[0]]
+    combined_value = enum_fields[combo[0]]
     for combo_name in combo[1:]:
-        combined_value |= current_mapping[combo_name]
-    enum_fields.append((name, combined_value))
-
-current_mapping = dict(enum_fields)
-enum_fields.extend((alias, current_mapping[name]) for alias, name in enum_aliases)
+        combined_value |= enum_fields[combo_name]
+    enum_fields[name] = combined_value
 
-# Finally, extract out the enum field names and their values.
-enum_field_names, enum_field_values = zip(*enum_fields)
+enum_fields.update(
+    (alias, enum_fields[name]) for alias, name in enum_aliases
+)
 
 
 # Subclass the namedtuple to improve the docstring.
 # noinspection PyUnresolvedReferences
-class _NSEnum(collections.namedtuple("_NSEnum", enum_field_names)):
+class _NSEnum(collections.namedtuple("_NSEnum", enum_fields.keys())):
     """
     Enum to control the `natsort` algorithm.
 
@@ -238,7 +235,7 @@ class _NSEnum(collections.namedtuple("_NSEnum", enum_field_names)):
 
 # Here is where the instance of the ns enum that will be exported is created.
 # It is a poor-man's singleton.
-ns = _NSEnum(*enum_field_values)
+ns = _NSEnum(*enum_fields.values())
 
 # The below is private for internal use only.
 ns_DUMB = 1 << 31
diff --git a/natsort/unicode_numeric_hex.py b/natsort/unicode_numeric_hex.py
index 56c69d6..de28f3b 100644
--- a/natsort/unicode_numeric_hex.py
+++ b/natsort/unicode_numeric_hex.py
@@ -1743,7 +1743,7 @@ if __name__ == "__main__":
             a = py23_unichr(i)
         except ValueError:
             break
-        if a in set("0123456789"):
+        if a in "0123456789":
             continue
         if unicodedata.numeric(a, None) is not None:
             hex_chars.append(i)
diff --git a/setup.cfg b/setup.cfg
index 3b44072..920a40d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -22,8 +22,8 @@ classifiers =
 	Operating System :: OS Independent
 	License :: OSI Approved :: MIT License
 	Natural Language :: English
+	Programming Language :: Python
 	Programming Language :: Python :: 2
-	Programming Language :: Python :: 2.6
 	Programming Language :: Python :: 2.7
 	Programming Language :: Python :: 3
 	Programming Language :: Python :: 3.4
diff --git a/setup.py b/setup.py
index 48f453a..7336da5 100644
--- a/setup.py
+++ b/setup.py
@@ -1,23 +1,14 @@
 #! /usr/bin/env python
 
-import sys
-
 from setuptools import find_packages, setup
-
-# Very old versions of setuptools do not support the python version
-# specifier syntax, so logic must be defined in code (see issue #64).
-install_requires = []
-extras_require = {"icu": "PyICU >= 1.0.0"}
-if sys.version_info[:2] == (2, 6):
-    install_requires.append("argparse")
-else:
-    extras_require["fast"] = "fastnumbers >= 2.0.0"
-
 setup(
     name='natsort',
     version='5.5.0',
     packages=find_packages(),
-    install_requires=install_requires,
     entry_points={'console_scripts': ['natsort = natsort.__main__:main']},
-    extras_require=extras_require,
+    python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
+    extras_require={
+        'fast': ["fastnumbers >= 2.0.0"],
+        'icu': ["PyICU >= 1.0.0"]
+    }
 )
diff --git a/test_natsort/conftest.py b/test_natsort/conftest.py
index 79a8aaa..8a7412b 100644
--- a/test_natsort/conftest.py
+++ b/test_natsort/conftest.py
@@ -10,9 +10,9 @@ import pytest
 def load_locale(x):
     """Convenience to load a locale, trying ISO8859-1 first."""
     try:
-        locale.setlocale(locale.LC_ALL, str("{0}.ISO8859-1".format(x)))
+        locale.setlocale(locale.LC_ALL, str("{}.ISO8859-1".format(x)))
     except locale.Error:
-        locale.setlocale(locale.LC_ALL, str("{0}.UTF-8".format(x)))
+        locale.setlocale(locale.LC_ALL, str("{}.UTF-8".format(x)))
 
 
 @pytest.fixture()
diff --git a/test_natsort/test_ns_enum.py b/test_natsort/test_ns_enum.py
new file mode 100644
index 0000000..1d3803b
--- /dev/null
+++ b/test_natsort/test_ns_enum.py
@@ -0,0 +1,44 @@
+from natsort import ns
+
+
+def test_ns_enum():
+    enum_name_values = [
+        ("FLOAT", 0x0001),
+        ("SIGNED", 0x0002),
+        ("NOEXP", 0x0004),
+        ("PATH", 0x0008),
+        ("LOCALEALPHA", 0x0010),
+        ("LOCALENUM", 0x0020),
+        ("IGNORECASE", 0x0040),
+        ("LOWERCASEFIRST", 0x0080),
+        ("GROUPLETTERS", 0x0100),
+        ("UNGROUPLETTERS", 0x0200),
+        ("NANLAST", 0x0400),
+        ("COMPATIBILITYNORMALIZE", 0x0800),
+        ("NUMAFTER", 0x1000),
+        ("DEFAULT", 0x0000),
+        ("INT", 0x0000),
+        ("UNSIGNED", 0x0000),
+        ("REAL", 0x0003),
+        ("LOCALE", 0x0030),
+        ("I", 0x0000),
+        ("U", 0x0000),
+        ("F", 0x0001),
+        ("S", 0x0002),
+        ("R", 0x0003),
+        ("N", 0x0004),
+        ("P", 0x0008),
+        ("LA", 0x0010),
+        ("LN", 0x0020),
+        ("L", 0x0030),
+        ("IC", 0x0040),
+        ("LF", 0x0080),
+        ("G", 0x0100),
+        ("UG", 0x0200),
+        ("C", 0x0200),
+        ("CAPITALFIRST", 0x0200),
+        ("NL", 0x0400),
+        ("CN", 0x0800),
+        ("NA", 0x1000),
+    ]
+    assert list(ns._asdict().items()) == enum_name_values
diff --git a/test_natsort/test_unicode_numbers.py b/test_natsort/test_unicode_numbers.py
index 484fbb2..582a8f0 100644
--- a/test_natsort/test_unicode_numbers.py
+++ b/test_natsort/test_unicode_numbers.py
@@ -45,7 +45,7 @@ def test_numeric_chars_contains_all_valid_unicode_numeric_and_digit_characters()
             a = py23_unichr(i)
         except ValueError:
             break
-        if a in set("0123456789"):
+        if a in "0123456789":
             continue
         if unicodedata.numeric(a, None) is not None:
             assert i in set_numeric_hex