Merge pull request #250 from python/debt/py36

Require Python 3.6

Author: jaraco

.github/workflows/main.yml

@@ -6,7 +6,7 @@ jobs:
   test:
     strategy:
       matrix:
-        python: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9]
+        python: [3.6, 3.7, 3.8, 3.9]
         platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:

coverage.ini

@@ -17,7 +17,6 @@ exclude_lines =
     raise NotImplementedError
     raise AssertionError
     assert\s
-    nocoverpy${PYV}
 
 [paths]
 source =

docs/changelog.rst

@@ -2,6 +2,11 @@
  importlib_metadata NEWS
 =========================
 
+v3.0.0
+======
+
+* Require Python 3.6 or later.
+
 v2.0.0
 ======
 

importlib_metadata/__init__.py

@@ -1,43 +1,31 @@
-from __future__ import unicode_literals, absolute_import
-
 import io
 import os
 import re
 import abc
 import csv
 import sys
 import zipp
+import email
+import pathlib
 import operator
 import functools
 import itertools
 import posixpath
 import collections
 
 from ._compat import (
-    install,
     NullFinder,
-    ConfigParser,
-    suppress,
-    map,
-    FileNotFoundError,
-    IsADirectoryError,
-    NotADirectoryError,
-    PermissionError,
-    pathlib,
-    ModuleNotFoundError,
-    MetaPathFinder,
-    email_message_from_string,
     PyPy_repr,
-    unique_ordered,
-    str,
+    install,
     )
+
+from configparser import ConfigParser
+from contextlib import suppress
 from importlib import import_module
+from importlib.abc import MetaPathFinder
 from itertools import starmap
 
 
-__metaclass__ = type
-
-
 __all__ = [
     'Distribution',
     'DistributionFinder',
@@ -277,7 +265,7 @@ def metadata(self):
             # (which points to the egg-info file) attribute unchanged.
             or self.read_text('')
             )
-        return email_message_from_string(text)
+        return email.message_from_string(text)
 
     @property
     def version(self):
@@ -457,7 +445,7 @@ def zip_children(self):
         names = zip_path.root.namelist()
         self.joinpath = zip_path.joinpath
 
-        return unique_ordered(
+        return dict.fromkeys(
             child.split(posixpath.sep, 1)[0]
             for child in names
             )

importlib_metadata/_compat.py

@@ -1,59 +1,7 @@
-from __future__ import absolute_import, unicode_literals
-
-import io
-import abc
 import sys
-import email
-
-
-if sys.version_info > (3,):  # pragma: nocover
-    import builtins
-    from configparser import ConfigParser
-    import contextlib
-    FileNotFoundError = builtins.FileNotFoundError
-    IsADirectoryError = builtins.IsADirectoryError
-    NotADirectoryError = builtins.NotADirectoryError
-    PermissionError = builtins.PermissionError
-    map = builtins.map
-    from itertools import filterfalse
-else:  # pragma: nocover
-    from backports.configparser import ConfigParser
-    from itertools import imap as map  # type: ignore
-    from itertools import ifilterfalse as filterfalse
-    import contextlib2 as contextlib
-    FileNotFoundError = IOError, OSError
-    IsADirectoryError = IOError, OSError
-    NotADirectoryError = IOError, OSError
-    PermissionError = IOError, OSError
-
-str = type('')
-
-suppress = contextlib.suppress
-
-if sys.version_info > (3, 5):  # pragma: nocover
-    import pathlib
-else:  # pragma: nocover
-    import pathlib2 as pathlib
-
-try:
-    ModuleNotFoundError = builtins.FileNotFoundError
-except (NameError, AttributeError):  # pragma: nocover
-    ModuleNotFoundError = ImportError  # type: ignore
-
-
-if sys.version_info >= (3,):  # pragma: nocover
-    from importlib.abc import MetaPathFinder
-else:  # pragma: nocover
-    class MetaPathFinder(object):
-        __metaclass__ = abc.ABCMeta
 
 
-__metaclass__ = type
-__all__ = [
-    'install', 'NullFinder', 'MetaPathFinder', 'ModuleNotFoundError',
-    'pathlib', 'ConfigParser', 'map', 'suppress', 'FileNotFoundError',
-    'NotADirectoryError', 'email_message_from_string',
-    ]
+__all__ = ['install', 'NullFinder', 'PyPy_repr']
 
 
 def install(cls):
@@ -104,20 +52,6 @@ def find_spec(*args, **kwargs):
     find_module = find_spec
 
 
-def py2_message_from_string(text):  # nocoverpy3
-    # Work around https://bugs.python.org/issue25545 where
-    # email.message_from_string cannot handle Unicode on Python 2.
-    io_buffer = io.StringIO(text)
-    return email.message_from_file(io_buffer)
-
-
-email_message_from_string = (
-    py2_message_from_string
-    if sys.version_info < (3,) else
-    email.message_from_string
-    )
-
-
 class PyPy_repr:
     """
     Override repr for EntryPoint objects on PyPy to avoid __iter__ access.
@@ -135,18 +69,3 @@ def make_param(name):
     if affected:  # pragma: nocover
         __repr__ = __compat_repr__
     del affected
-
-
-# from itertools recipes
-def unique_everseen(iterable):  # pragma: nocover
-    "List unique elements, preserving order. Remember all elements ever seen."
-    seen = set()
-    seen_add = seen.add
-
-    for element in filterfalse(seen.__contains__, iterable):
-        seen_add(element)
-        yield element
-
-
-unique_ordered = (
-    unique_everseen if sys.version_info < (3, 7) else dict.fromkeys)

setup.cfg

@@ -12,16 +12,12 @@ classifiers =
     License :: OSI Approved :: Apache Software License
     Topic :: Software Development :: Libraries
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 2
 
 [options]
-python_requires = >=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*
+python_requires = >=3.6
 setup_requires = setuptools-scm
 install_requires =
     zipp>=0.5
-    pathlib2; python_version < '3'
-    contextlib2; python_version < '3'
-    configparser>=3.5; python_version < '3'
 packages = importlib_metadata
 
 [mypy]

tests/fixtures.py

@@ -1,18 +1,13 @@
-from __future__ import unicode_literals
-
 import os
 import sys
 import shutil
+import pathlib
 import tempfile
 import textwrap
+import contextlib
 
 from .py39compat import FS_NONASCII
 
-from importlib_metadata._compat import pathlib, contextlib
-
-
-__metaclass__ = type
-
 
 @contextlib.contextmanager
 def tempdir():

tests/test_api.py

@@ -8,16 +8,6 @@
     entry_points, files, metadata, requires, version,
     )
 
-try:
-    from collections.abc import Iterator
-except ImportError:
-    from collections import Iterator  # noqa: F401
-
-try:
-    from builtins import str as text
-except ImportError:
-    from __builtin__ import unicode as text
-
 
 class APITests(
         fixtures.EggInfoPkg,
@@ -29,12 +19,12 @@ class APITests(
 
     def test_retrieves_version_of_self(self):
         pkg_version = version('egginfo-pkg')
-        assert isinstance(pkg_version, text)
+        assert isinstance(pkg_version, str)
         assert re.match(self.version_pattern, pkg_version)
 
     def test_retrieves_version_of_distinfo_pkg(self):
         pkg_version = version('distinfo-pkg')
-        assert isinstance(pkg_version, text)
+        assert isinstance(pkg_version, str)
         assert re.match(self.version_pattern, pkg_version)
 
     def test_for_name_does_not_exist(self):

tests/test_integration.py

@@ -1,7 +1,3 @@
-# coding: utf-8
-
-from __future__ import unicode_literals
-
 import unittest
 import packaging.requirements
 import packaging.version

tests/test_main.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import re
 import json
 import pickle
@@ -17,18 +14,13 @@
     entry_points, metadata, version,
     )
 
-try:
-    from builtins import str as text
-except ImportError:
-    from __builtin__ import unicode as text
-
 
 class BasicTests(fixtures.DistInfoPkg, unittest.TestCase):
     version_pattern = r'\d+\.\d+(\.\d)?'
 
     def test_retrieves_version_of_self(self):
         dist = Distribution.from_name('distinfo-pkg')
-        assert isinstance(dist.version, text)
+        assert isinstance(dist.version, str)
         assert re.match(self.version_pattern, dist.version)
 
     def test_for_name_does_not_exist(self):