Use unique_everseen from more_itertools.

4 files changed, 8 insertions, 66 deletions

diff --git a/setuptools/command/build_py.py b/setuptools/command/build_py.py
index b30aa129..df6fd323 100644
--- a/setuptools/command/build_py.py
+++ b/setuptools/command/build_py.py
@@ -8,6 +8,7 @@ import io
 import distutils.errors
 import itertools
 import stat
+from setuptools.extern.more_itertools import unique_everseen
 
 try:
     from setuptools.lib2to3_ex import Mixin2to3
@@ -214,7 +215,7 @@ class build_py(orig.build_py, Mixin2to3):
             if fn not in bad
         )
         # ditch dupes
-        return list(_unique_everseen(keepers))
+        return list(unique_everseen(keepers))
 
     @staticmethod
     def _get_platform_patterns(spec, package, src_dir):
@@ -235,25 +236,6 @@ class build_py(orig.build_py, Mixin2to3):
         )
 
 
-# from Python docs
-def _unique_everseen(iterable, key=None):
-    "List unique elements, preserving order. Remember all elements ever seen."
-    # unique_everseen('AAAABBBCCDAABBB') --> A B C D
-    # unique_everseen('ABBCcAD', str.lower) --> A B C D
-    seen = set()
-    seen_add = seen.add
-    if key is None:
-        for element in itertools.filterfalse(seen.__contains__, iterable):
-            seen_add(element)
-            yield element
-    else:
-        for element in iterable:
-            k = key(element)
-            if k not in seen:
-                seen_add(k)
-                yield element
-
-
 def assert_relative(path):
     if not os.path.isabs(path):
         return path
diff --git a/setuptools/command/test.py b/setuptools/command/test.py
index cf71ad01..de4f3d11 100644
--- a/setuptools/command/test.py
+++ b/setuptools/command/test.py
@@ -12,7 +12,7 @@ from pkg_resources import (resource_listdir, resource_exists, normalize_path,
                            working_set, _namespace_packages, evaluate_marker,
                            add_activation_listener, require, EntryPoint)
 from setuptools import Command
-from .build_py import _unique_everseen
+from setuptools.extern.more_itertools import unique_everseen
 
 
 class ScanningLoader(TestLoader):
@@ -182,7 +182,7 @@ class test(Command):
         orig_pythonpath = os.environ.get('PYTHONPATH', nothing)
         current_pythonpath = os.environ.get('PYTHONPATH', '')
         try:
-            prefix = os.pathsep.join(_unique_everseen(paths))
+            prefix = os.pathsep.join(unique_everseen(paths))
             to_join = filter(None, [prefix, current_pythonpath])
             new_path = os.pathsep.join(to_join)
             if new_path:
diff --git a/setuptools/msvc.py b/setuptools/msvc.py
index fd4b0781..281ea1c2 100644
--- a/setuptools/msvc.py
+++ b/setuptools/msvc.py
@@ -30,6 +30,7 @@ import itertools
 import subprocess
 import distutils.errors
 from setuptools.extern.packaging.version import LegacyVersion
+from setuptools.extern.more_itertools import unique_everseen
 
 from .monkey import get_unpatched
 
@@ -1800,29 +1801,5 @@ class EnvironmentInfo:
         if not extant_paths:
             msg = "%s environment variable is empty" % name.upper()
             raise distutils.errors.DistutilsPlatformError(msg)
-        unique_paths = self._unique_everseen(extant_paths)
+        unique_paths = unique_everseen(extant_paths)
         return pathsep.join(unique_paths)
-
-    # from Python docs
-    @staticmethod
-    def _unique_everseen(iterable, key=None):
-        """
-        List unique elements, preserving order.
-        Remember all elements ever seen.
-
-        _unique_everseen('AAAABBBCCDAABBB') --> A B C D
-
-        _unique_everseen('ABBCcAD', str.lower) --> A B C D
-        """
-        seen = set()
-        seen_add = seen.add
-        if key is None:
-            for element in itertools.filterfalse(seen.__contains__, iterable):
-                seen_add(element)
-                yield element
-        else:
-            for element in iterable:
-                k = key(element)
-                if k not in seen:
-                    seen_add(k)
-                    yield element
diff --git a/setuptools/package_index.py b/setuptools/package_index.py
index 8bec05e7..d1f13378 100644
--- a/setuptools/package_index.py
+++ b/setuptools/package_index.py
@@ -28,6 +28,8 @@ from distutils import log
 from distutils.errors import DistutilsError
 from fnmatch import translate
 from setuptools.wheel import Wheel
+from setuptools.extern.more_itertools import unique_everseen
+
 
 EGG_FRAGMENT = re.compile(r'^egg=([-A-Za-z0-9_.+!]+)$')
 HREF = re.compile(r"""href\s*=\s*['"]?([^'"> ]+)""", re.I)
@@ -183,25 +185,6 @@ def interpret_distro_name(
         )
 
 
-# From Python 2.7 docs
-def unique_everseen(iterable, key=None):
-    "List unique elements, preserving order. Remember all elements ever seen."
-    # unique_everseen('AAAABBBCCDAABBB') --> A B C D
-    # unique_everseen('ABBCcAD', str.lower) --> A B C D
-    seen = set()
-    seen_add = seen.add
-    if key is None:
-        for element in itertools.filterfalse(seen.__contains__, iterable):
-            seen_add(element)
-            yield element
-    else:
-        for element in iterable:
-            k = key(element)
-            if k not in seen:
-                seen_add(k)
-                yield element
-
-
 def unique_values(func):
     """
     Wrap a function returning an iterable such that the resulting iterable