Merge with 8.0b1 (use packaging for version specifiers)8.0

19 files changed, 1425 insertions, 195 deletions

diff --git a/.hgtags b/.hgtags
index 7e995132..5d8d2873 100644
--- a/.hgtags
+++ b/.hgtags
@@ -160,3 +160,4 @@ bc6655b4acf205dd9f25c702955645656077398a 6.0.1
 01271e84e5125fcc4f0f368a6e21116a5722953c 6.0.2
 7ea80190d494a766c6356fce85c844703964b6cc 6.1
 df26609c2f614f5fc9110342e4003ee8bd95cf84 7.0
+850a5c155c48b6ecfbb83b961586ea359b561522 8.0b1
diff --git a/CHANGES.txt b/CHANGES.txt
index 49529a04..cc2423b6 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -3,6 +3,19 @@ CHANGES
 =======
 
 ---
+8.0
+---
+
+* Implement `PEP 440 <http://legacy.python.org/dev/peps/pep-0440/>`_ within
+  pkg_resources and setuptools. This change
+  deprecates some version numbers such that they will no longer be installable
+  without using the ``===`` escape hatch. See `the changes to test_resources
+  <https://bitbucket.org/pypa/setuptools/commits/dcd552da643c4448056de84c73d56da6d70769d5#chg-setuptools/tests/test_resources.py>`_
+  for specific examples of version numbers and specifiers that are no longer
+  supported. Setuptools now "vendors" the `packaging
+  <https://github.com/pypa/packaging>`_ library.
+
+---
 7.0
 ---
 
diff --git a/Makefile b/Makefile
new file mode 100644
index 00000000..ab60b882
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+empty:
+	exit 1
+
+update-vendored:
+	rm -rf setuptools/_vendor/packaging
+	pip install -r setuptools/_vendor/vendored.txt -t setuptools/_vendor/
+	rm -rf setuptools/_vendor/*.{egg,dist}-info
diff --git a/docs/pkg_resources.txt b/docs/pkg_resources.txt
index f4a768e4..6c6405a8 100644
--- a/docs/pkg_resources.txt
+++ b/docs/pkg_resources.txt
@@ -594,7 +594,7 @@ Requirements Parsing
 
         requirement  ::= project_name versionspec? extras?
         versionspec  ::= comparison version (',' comparison version)*
-        comparison   ::= '<' | '<=' | '!=' | '==' | '>=' | '>'
+        comparison   ::= '<' | '<=' | '!=' | '==' | '>=' | '>' | '~=' | '==='
         extras       ::= '[' extralist? ']'
         extralist    ::= identifier (',' identifier)*
         project_name ::= identifier
@@ -646,13 +646,10 @@ Requirements Parsing
     The ``Requirement`` object's version specifiers (``.specs``) are internally
     sorted into ascending version order, and used to establish what ranges of
     versions are acceptable.  Adjacent redundant conditions are effectively
-    consolidated (e.g. ``">1, >2"`` produces the same results as ``">1"``, and
-    ``"<2,<3"`` produces the same results as``"<3"``). ``"!="`` versions are
+    consolidated (e.g. ``">1, >2"`` produces the same results as ``">2"``, and
+    ``"<2,<3"`` produces the same results as``"<2"``). ``"!="`` versions are
     excised from the ranges they fall within.  The version being tested for
     acceptability is then checked for membership in the resulting ranges.
-    (Note that providing conflicting conditions for the same version (e.g.
-    ``"<2,>=2"`` or ``"==2,!=2"``) is meaningless and may therefore produce
-    bizarre results when compared with actual version number(s).)
 
 ``__eq__(other_requirement)``
     A requirement compares equal to another requirement if they have
@@ -681,10 +678,7 @@ Requirements Parsing
 ``specs``
     A list of ``(op,version)`` tuples, sorted in ascending parsed-version
     order.  The `op` in each tuple is a comparison operator, represented as
-    a string.  The `version` is the (unparsed) version number.  The relative
-    order of tuples containing the same version numbers is undefined, since
-    having more than one operator for a given version is either redundant or
-    self-contradictory.
+    a string.  The `version` is the (unparsed) version number.
 
 
 Entry Points
@@ -967,7 +961,7 @@ version
     ``ValueError`` is raised.
 
 parsed_version
-    The ``parsed_version`` is a tuple representing a "parsed" form of the
+    The ``parsed_version`` is an object representing a "parsed" form of the
     distribution's ``version``.  ``dist.parsed_version`` is a shortcut for
     calling ``parse_version(dist.version)``.  It is used to compare or sort
     distributions by version.  (See the `Parsing Utilities`_ section below for
@@ -1541,40 +1535,12 @@ Parsing Utilities
 -----------------
 
 ``parse_version(version)``
-    Parse a project's version string, returning a value that can be used to
-    compare versions by chronological order.  Semantically, the format is a
-    rough cross between distutils' ``StrictVersion`` and ``LooseVersion``
-    classes; if you give it versions that would work with ``StrictVersion``,
-    then they will compare the same way.  Otherwise, comparisons are more like
-    a "smarter" form of ``LooseVersion``.  It is *possible* to create
-    pathological version coding schemes that will fool this parser, but they
-    should be very rare in practice.
-
-    The returned value will be a tuple of strings.  Numeric portions of the
-    version are padded to 8 digits so they will compare numerically, but
-    without relying on how numbers compare relative to strings.  Dots are
-    dropped, but dashes are retained.  Trailing zeros between alpha segments
-    or dashes are suppressed, so that e.g. "2.4.0" is considered the same as
-    "2.4". Alphanumeric parts are lower-cased.
-
-    The algorithm assumes that strings like "-" and any alpha string that
-    alphabetically follows "final"  represents a "patch level".  So, "2.4-1"
-    is assumed to be a branch or patch of "2.4", and therefore "2.4.1" is
-    considered newer than "2.4-1", which in turn is newer than "2.4".
-
-    Strings like "a", "b", "c", "alpha", "beta", "candidate" and so on (that
-    come before "final" alphabetically) are assumed to be pre-release versions,
-    so that the version "2.4" is considered newer than "2.4a1".  Any "-"
-    characters preceding a pre-release indicator are removed.  (In versions of
-    setuptools prior to 0.6a9, "-" characters were not removed, leading to the
-    unintuitive result that "0.2-rc1" was considered a newer version than
-    "0.2".)
-
-    Finally, to handle miscellaneous cases, the strings "pre", "preview", and
-    "rc" are treated as if they were "c", i.e. as though they were release
-    candidates, and therefore are not as new as a version string that does not
-    contain them.  And the string "dev" is treated as if it were an "@" sign;
-    that is, a version coming before even "a" or "alpha".
+    Parsed a project's version string as defined by PEP 440. The returned
+    value will be an object that represents the version. These objects may
+    be compared to each other and sorted. The sorting algorithm is as defined
+    by PEP 440 with the addition that any version which is not a valid PEP 440
+    version will be considered less than any valid PEP 440 version and the
+    invalid versions will continue sorting using the original algorithm.
 
 .. _yield_lines():
 
@@ -1629,10 +1595,12 @@ Parsing Utilities
     See ``to_filename()``.
 
 ``safe_version(version)``
-    Similar to ``safe_name()`` except that spaces in the input become dots, and
-    dots are allowed to exist in the output.  As with ``safe_name()``, if you
-    are generating a filename from this you should replace any "-" characters
-    in the output with underscores.
+    This will return the normalized form of any PEP 440 version, if the version
+    string is not PEP 440 compatible than it is similar to ``safe_name()``
+    except that spaces in the input become dots, and dots are allowed to exist
+    in the output.  As with ``safe_name()``, if you are generating a filename
+    from this you should replace any "-" characters in the output with
+    underscores.
 
 ``safe_extra(extra)``
     Return a "safe" form of an extra's name, suitable for use in a requirement
diff --git a/ez_setup.py b/ez_setup.py
index 86647613..f6361e8e 100644
--- a/ez_setup.py
+++ b/ez_setup.py
@@ -36,7 +36,7 @@ try:
 except ImportError:
     USER_SITE = None
 
-DEFAULT_VERSION = "7.1"
+DEFAULT_VERSION = "8.0"
 DEFAULT_URL = "https://pypi.python.org/packages/source/s/setuptools/"
 
 def _python_cmd(*args):
diff --git a/pkg_resources.py b/pkg_resources.py
index 511068a6..a3eef28f 100644
--- a/pkg_resources.py
+++ b/pkg_resources.py
@@ -14,6 +14,8 @@ The package resource API is designed to work with normal filesystem packages,
 method.
 """
 
+from __future__ import absolute_import
+
 import sys
 import os
 import io
@@ -73,6 +75,13 @@ try:
 except ImportError:
     pass
 
+import setuptools._vendor.packaging.version
+import setuptools._vendor.packaging.specifiers
+packaging = setuptools._vendor.packaging
+
+# For compatibility, expose packaging.version.parse as parse_version
+parse_version = packaging.version.parse
+
 
 _state_vars = {}
 
@@ -1156,13 +1165,15 @@ def safe_name(name):
 
 
 def safe_version(version):
-    """Convert an arbitrary string to a standard version string
-
-    Spaces become dots, and all other non-alphanumeric characters become
-    dashes, with runs of multiple dashes condensed to a single dash.
     """
-    version = version.replace(' ','.')
-    return re.sub('[^A-Za-z0-9.]+', '-', version)
+    Convert an arbitrary string to a standard version string
+    """
+    try:
+        # normalize the version
+        return str(packaging.version.Version(version))
+    except packaging.version.InvalidVersion:
+        version = version.replace(' ','.')
+        return re.sub('[^A-Za-z0-9.]+', '-', version)
 
 
 def safe_extra(extra):
@@ -2080,7 +2091,7 @@ CONTINUE = re.compile(r"\s*\\\s*(#.*)?$").match
 # Distribution or extra
 DISTRO = re.compile(r"\s*((\w|[-.])+)").match
 # ver. info
-VERSION = re.compile(r"\s*(<=?|>=?|==|!=)\s*((\w|[-.])+)").match
+VERSION = re.compile(r"\s*(<=?|>=?|===?|!=|~=)\s*((\w|[-.*_!+])+)").match
 # comma between items
 COMMA = re.compile(r"\s*,").match
 OBRACKET = re.compile(r"\s*\[").match
@@ -2092,67 +2103,6 @@ EGG_NAME = re.compile(
     re.VERBOSE | re.IGNORECASE
 ).match
 
-component_re = re.compile(r'(\d+ | [a-z]+ | \.| -)', re.VERBOSE)
-replace = {'pre':'c', 'preview':'c','-':'final-','rc':'c','dev':'@'}.get
-
-def _parse_version_parts(s):
-    for part in component_re.split(s):
-        part = replace(part, part)
-        if not part or part=='.':
-            continue
-        if part[:1] in '0123456789':
-            # pad for numeric comparison
-            yield part.zfill(8)
-        else:
-            yield '*'+part
-
-    # ensure that alpha/beta/candidate are before final
-    yield '*final'
-
-def parse_version(s):
-    """Convert a version string to a chronologically-sortable key
-
-    This is a rough cross between distutils' StrictVersion and LooseVersion;
-    if you give it versions that would work with StrictVersion, then it behaves
-    the same; otherwise it acts like a slightly-smarter LooseVersion. It is
-    *possible* to create pathological version coding schemes that will fool
-    this parser, but they should be very rare in practice.
-
-    The returned value will be a tuple of strings.  Numeric portions of the
-    version are padded to 8 digits so they will compare numerically, but
-    without relying on how numbers compare relative to strings.  Dots are
-    dropped, but dashes are retained.  Trailing zeros between alpha segments
-    or dashes are suppressed, so that e.g. "2.4.0" is considered the same as
-    "2.4". Alphanumeric parts are lower-cased.
-
-    The algorithm assumes that strings like "-" and any alpha string that
-    alphabetically follows "final"  represents a "patch level".  So, "2.4-1"
-    is assumed to be a branch or patch of "2.4", and therefore "2.4.1" is
-    considered newer than "2.4-1", which in turn is newer than "2.4".
-
-    Strings like "a", "b", "c", "alpha", "beta", "candidate" and so on (that
-    come before "final" alphabetically) are assumed to be pre-release versions,
-    so that the version "2.4" is considered newer than "2.4a1".
-
-    Finally, to handle miscellaneous cases, the strings "pre", "preview", and
-    "rc" are treated as if they were "c", i.e. as though they were release
-    candidates, and therefore are not as new as a version string that does not
-    contain them, and "dev" is replaced with an '@' so that it sorts lower than
-    than any other pre-release tag.
-    """
-    parts = []
-    for part in _parse_version_parts(s.lower()):
-        if part.startswith('*'):
-            # remove '-' before a prerelease tag
-            if part < '*final':
-                while parts and parts[-1] == '*final-':
-                    parts.pop()
-            # remove trailing zeros from each series of numeric parts
-            while parts and parts[-1]=='00000000':
-                parts.pop()
-        parts.append(part)
-    return tuple(parts)
-
 
 class EntryPoint(object):
     """Object representing an advertised importable object"""
@@ -2305,7 +2255,7 @@ class Distribution(object):
     @property
     def hashcmp(self):
         return (
-            getattr(self, 'parsed_version', ()),
+            self.parsed_version,
             self.precedence,
             self.key,
             _remove_md5_fragment(self.location),
@@ -2351,11 +2301,10 @@ class Distribution(object):
 
     @property
     def parsed_version(self):
-        try:
-            return self._parsed_version
-        except AttributeError:
-            self._parsed_version = pv = parse_version(self.version)
-            return pv
+        if not hasattr(self, "_parsed_version"):
+            self._parsed_version = parse_version(self.version)
+
+        return self._parsed_version
 
     @property
     def version(self):
@@ -2460,7 +2409,12 @@ class Distribution(object):
 
     def as_requirement(self):
         """Return a ``Requirement`` that matches this distribution exactly"""
-        return Requirement.parse('%s==%s' % (self.project_name, self.version))
+        if isinstance(self.parsed_version, packaging.version.Version):
+            spec = "%s==%s" % (self.project_name, self.parsed_version)
+        else:
+            spec = "%s===%s" % (self.project_name, self.parsed_version)
+
+        return Requirement.parse(spec)
 
     def load_entry_point(self, group, name):
         """Return the `name` entry point of `group` or raise ImportError"""
@@ -2712,7 +2666,7 @@ def parse_requirements(strs):
 
         line, p, specs = scan_list(VERSION, LINE_END, line, p, (1, 2),
             "version spec")
-        specs = [(op, safe_version(val)) for op, val in specs]
+        specs = [(op, val) for op, val in specs]
         yield Requirement(project_name, specs, extras)
 
 
@@ -2721,26 +2675,23 @@ class Requirement:
         """DO NOT CALL THIS UNDOCUMENTED METHOD; use Requirement.parse()!"""
         self.unsafe_name, project_name = project_name, safe_name(project_name)
         self.project_name, self.key = project_name, project_name.lower()
-        index = [
-            (parse_version(v), state_machine[op], op, v)
-            for op, v in specs
-        ]
-        index.sort()
-        self.specs = [(op, ver) for parsed, trans, op, ver in index]
-        self.index, self.extras = index, tuple(map(safe_extra, extras))
+        self.specifier = packaging.specifiers.SpecifierSet(
+            ",".join(["".join([x, y]) for x, y in specs])
+        )
+        self.specs = specs
+        self.extras = tuple(map(safe_extra, extras))
         self.hashCmp = (
             self.key,
-            tuple((op, parsed) for parsed, trans, op, ver in index),
+            self.specifier,
             frozenset(self.extras),
         )
         self.__hash = hash(self.hashCmp)
 
     def __str__(self):
-        specs = ','.join([''.join(s) for s in self.specs])
         extras = ','.join(self.extras)
         if extras:
             extras = '[%s]' % extras
-        return '%s%s%s' % (self.project_name, extras, specs)
+        return '%s%s%s' % (self.project_name, extras, self.specifier)
 
     def __eq__(self, other):
         return (
@@ -2752,29 +2703,13 @@ class Requirement:
         if isinstance(item, Distribution):
             if item.key != self.key:
                 return False
-            # only get if we need it
-            if self.index:
-                item = item.parsed_version
-        elif isinstance(item, string_types):
-            item = parse_version(item)
-        last = None
-        # -1, 0, 1
-        compare = lambda a, b: (a > b) - (a < b)
-        for parsed, trans, op, ver in self.index:
-            # Indexing: 0, 1, -1
-            action = trans[compare(item, parsed)]
-            if action == 'F':
-                return False
-            elif action == 'T':
-                return True
-            elif action == '+':
-                last = True
-            elif action == '-' or last is None:
-                last = False
-        # no rules encountered
-        if last is None:
-            last = True
-        return last
+
+            item = item.version
+
+        # Allow prereleases always in order to match the previous behavior of
+        # this method. In the future this should be smarter and follow PEP 440
+        # more accurately.
+        return self.specifier.contains(item, prereleases=True)
 
     def __hash__(self):
         return self.__hash
@@ -2790,16 +2725,6 @@ class Requirement:
             raise ValueError("Expected only one requirement", s)
         raise ValueError("No requirements found", s)
 
-state_machine = {
-    #       =><
-    '<': '--T',
-    '<=': 'T-T',
-    '>': 'F+F',
-    '>=': 'T+F',
-    '==': 'T..',
-    '!=': 'F++',
-}
-
 
 def _get_mro(cls):
     """Get an mro for a type or classic class"""
diff --git a/setuptools/_vendor/__init__.py b/setuptools/_vendor/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/setuptools/_vendor/__init__.py
diff --git a/setuptools/_vendor/packaging/__about__.py b/setuptools/_vendor/packaging/__about__.py
new file mode 100644
index 00000000..481589e7
--- /dev/null
+++ b/setuptools/_vendor/packaging/__about__.py
@@ -0,0 +1,31 @@
+# Copyright 2014 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
+__all__ = [
+    "__title__", "__summary__", "__uri__", "__version__", "__author__",
+    "__email__", "__license__", "__copyright__",
+]
+
+__title__ = "packaging"
+__summary__ = "Core utilities for Python packages"
+__uri__ = "https://github.com/pypa/packaging"
+
+__version__ = "14.3"
+
+__author__ = "Donald Stufft"
+__email__ = "donald@stufft.io"
+
+__license__ = "Apache License, Version 2.0"
+__copyright__ = "Copyright 2014 %s" % __author__
diff --git a/setuptools/_vendor/packaging/__init__.py b/setuptools/_vendor/packaging/__init__.py
new file mode 100644
index 00000000..c39a8eab
--- /dev/null
+++ b/setuptools/_vendor/packaging/__init__.py
@@ -0,0 +1,24 @@
+# Copyright 2014 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
+from .__about__ import (
+    __author__, __copyright__, __email__, __license__, __summary__, __title__,
+    __uri__, __version__
+)
+
+__all__ = [
+    "__title__", "__summary__", "__uri__", "__version__", "__author__",
+    "__email__", "__license__", "__copyright__",
+]
diff --git a/setuptools/_vendor/packaging/_compat.py b/setuptools/_vendor/packaging/_compat.py
new file mode 100644
index 00000000..5c396cea
--- /dev/null
+++ b/setuptools/_vendor/packaging/_compat.py
@@ -0,0 +1,40 @@
+# Copyright 2014 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
+import sys
+
+
+PY2 = sys.version_info[0] == 2
+PY3 = sys.version_info[0] == 3
+
+# flake8: noqa
+
+if PY3:
+    string_types = str,
+else:
+    string_types = basestring,
+
+
+def with_metaclass(meta, *bases):
+    """
+    Create a base class with a metaclass.
+    """
+    # This requires a bit of explanation: the basic idea is to make a dummy
+    # metaclass for one level of class instantiation that replaces itself with
+    # the actual metaclass.
+    class metaclass(meta):
+        def __new__(cls, name, this_bases, d):
+            return meta(name, bases, d)
+    return type.__new__(metaclass, 'temporary_class', (), {})
diff --git a/setuptools/_vendor/packaging/_structures.py b/setuptools/_vendor/packaging/_structures.py
new file mode 100644
index 00000000..0ae9bb52
--- /dev/null
+++ b/setuptools/_vendor/packaging/_structures.py
@@ -0,0 +1,78 @@
+# Copyright 2014 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
+
+class Infinity(object):
+
+    def __repr__(self):
+        return "Infinity"
+
+    def __hash__(self):
+        return hash(repr(self))
+
+    def __lt__(self, other):
+        return False
+
+    def __le__(self, other):
+        return False
+
+    def __eq__(self, other):
+        return isinstance(other, self.__class__)
+
+    def __ne__(self, other):
+        return not isinstance(other, self.__class__)
+
+    def __gt__(self, other):
+        return True
+
+    def __ge__(self, other):
+        return True
+
+    def __neg__(self):
+        return NegativeInfinity
+
+Infinity = Infinity()
+
+
+class NegativeInfinity(object):
+
+    def __repr__(self):
+        return "-Infinity"
+
+    def __hash__(self):
+        return hash(repr(self))
+
+    def __lt__(self, other):
+        return True
+
+    def __le__(self, other):
+        return True
+
+    def __eq__(self, other):
+        return isinstance(other, self.__class__)
+
+    def __ne__(self, other):
+        return not isinstance(other, self.__class__)
+
+    def __gt__(self, other):
+        return False
+
+    def __ge__(self, other):
+        return False
+
+    def __neg__(self):
+        return Infinity
+
+NegativeInfinity = NegativeInfinity()
diff --git a/setuptools/_vendor/packaging/specifiers.py b/setuptools/_vendor/packaging/specifiers.py
new file mode 100644
index 00000000..bea4a398
--- /dev/null
+++ b/setuptools/_vendor/packaging/specifiers.py
@@ -0,0 +1,732 @@
+# Copyright 2014 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
+import abc
+import functools
+import itertools
+import re
+
+from ._compat import string_types, with_metaclass
+from .version import Version, LegacyVersion, parse
+
+
+class InvalidSpecifier(ValueError):
+    """
+    An invalid specifier was found, users should refer to PEP 440.
+    """
+
+
+class BaseSpecifier(with_metaclass(abc.ABCMeta, object)):
+
+    @abc.abstractmethod
+    def __str__(self):
+        """
+        Returns the str representation of this Specifier like object. This
+        should be representative of the Specifier itself.
+        """
+
+    @abc.abstractmethod
+    def __hash__(self):
+        """
+        Returns a hash value for this Specifier like object.
+        """
+
+    @abc.abstractmethod
+    def __eq__(self, other):
+        """
+        Returns a boolean representing whether or not the two Specifier like
+        objects are equal.
+        """
+
+    @abc.abstractmethod
+    def __ne__(self, other):
+        """
+        Returns a boolean representing whether or not the two Specifier like
+        objects are not equal.
+        """
+
+    @abc.abstractproperty
+    def prereleases(self):
+        """
+        Returns whether or not pre-releases as a whole are allowed by this
+        specifier.
+        """
+
+    @prereleases.setter
+    def prereleases(self, value):
+        """
+        Sets whether or not pre-releases as a whole are allowed by this
+        specifier.
+        """
+
+    @abc.abstractmethod
+    def contains(self, item, prereleases=None):
+        """
+        Determines if the given item is contained within this specifier.
+        """
+
+    @abc.abstractmethod
+    def filter(self, iterable, prereleases=None):
+        """
+        Takes an iterable of items and filters them so that only items which
+        are contained within this specifier are allowed in it.
+        """
+
+
+class _IndividualSpecifier(BaseSpecifier):
+
+    _operators = {}
+
+    def __init__(self, spec="", prereleases=None):
+        match = self._regex.search(spec)
+        if not match:
+            raise InvalidSpecifier("Invalid specifier: '{0}'".format(spec))
+
+        self._spec = (
+            match.group("operator").strip(),
+            match.group("version").strip(),
+        )
+
+        # Store whether or not this Specifier should accept prereleases
+        self._prereleases = prereleases
+
+    def __repr__(self):
+        pre = (
+            ", prereleases={0!r}".format(self.prereleases)
+            if self._prereleases is not None
+            else ""
+        )
+
+        return "<{0}({1!r}{2})>".format(
+            self.__class__.__name__,
+            str(self),
+            pre,
+        )
+
+    def __str__(self):
+        return "{0}{1}".format(*self._spec)
+
+    def __hash__(self):
+        return hash(self._spec)
+
+    def __eq__(self, other):
+        if isinstance(other, string_types):
+            try:
+                other = self.__class__(other)
+            except InvalidSpecifier:
+                return NotImplemented
+        elif not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self._spec == other._spec
+
+    def __ne__(self, other):
+        if isinstance(other, string_types):
+            try:
+                other = self.__class__(other)
+            except InvalidSpecifier:
+                return NotImplemented
+        elif not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self._spec != other._spec
+
+    def _get_operator(self, op):
+        return getattr(self, "_compare_{0}".format(self._operators[op]))
+
+    def _coerce_version(self, version):
+        if not isinstance(version, (LegacyVersion, Version)):
+            version = parse(version)
+        return version
+
+    @property
+    def prereleases(self):
+        return self._prereleases
+
+    @prereleases.setter
+    def prereleases(self, value):
+        self._prereleases = value
+
+    def contains(self, item, prereleases=None):
+        # Determine if prereleases are to be allowed or not.
+        if prereleases is None:
+            prereleases = self.prereleases
+
+        # Normalize item to a Version or LegacyVersion, this allows us to have
+        # a shortcut for ``"2.0" in Specifier(">=2")
+        item = self._coerce_version(item)
+
+        # Determine if we should be supporting prereleases in this specifier
+        # or not, if we do not support prereleases than we can short circuit
+        # logic if this version is a prereleases.
+        if item.is_prerelease and not prereleases:
+            return False
+
+        # Actually do the comparison to determine if this item is contained
+        # within this Specifier or not.
+        return self._get_operator(self._spec[0])(item, self._spec[1])
+
+    def filter(self, iterable, prereleases=None):
+        yielded = False
+        found_prereleases = []
+
+        kw = {"prereleases": prereleases if prereleases is not None else True}
+
+        # Attempt to iterate over all the values in the iterable and if any of
+        # them match, yield them.
+        for version in iterable:
+            parsed_version = self._coerce_version(version)
+
+            if self.contains(parsed_version, **kw):
+                # If our version is a prerelease, and we were not set to allow
+                # prereleases, then we'll store it for later incase nothing
+                # else matches this specifier.
+                if (parsed_version.is_prerelease
+                        and not (prereleases or self.prereleases)):
+                    found_prereleases.append(version)
+                # Either this is not a prerelease, or we should have been
+                # accepting prereleases from the begining.
+                else:
+                    yielded = True
+                    yield version
+
+        # Now that we've iterated over everything, determine if we've yielded
+        # any values, and if we have not and we have any prereleases stored up
+        # then we will go ahead and yield the prereleases.
+        if not yielded and found_prereleases:
+            for version in found_prereleases:
+                yield version
+
+
+class LegacySpecifier(_IndividualSpecifier):
+
+    _regex = re.compile(
+        r"""
+        ^
+        \s*
+        (?P<operator>(==|!=|<=|>=|<|>))
+        \s*
+        (?P<version>
+            [^\s]* # We just match everything, except for whitespace since this
+                   # is a "legacy" specifier and the version string can be just
+                   # about anything.
+        )
+        \s*
+        $
+        """,
+        re.VERBOSE | re.IGNORECASE,
+    )
+
+    _operators = {
+        "==": "equal",
+        "!=": "not_equal",
+        "<=": "less_than_equal",
+        ">=": "greater_than_equal",
+        "<": "less_than",
+        ">": "greater_than",
+    }
+
+    def _coerce_version(self, version):
+        if not isinstance(version, LegacyVersion):
+            version = LegacyVersion(str(version))
+        return version
+
+    def _compare_equal(self, prospective, spec):
+        return prospective == self._coerce_version(spec)
+
+    def _compare_not_equal(self, prospective, spec):
+        return prospective != self._coerce_version(spec)
+
+    def _compare_less_than_equal(self, prospective, spec):
+        return prospective <= self._coerce_version(spec)
+
+    def _compare_greater_than_equal(self, prospective, spec):
+        return prospective >= self._coerce_version(spec)
+
+    def _compare_less_than(self, prospective, spec):
+        return prospective < self._coerce_version(spec)
+
+    def _compare_greater_than(self, prospective, spec):
+        return prospective > self._coerce_version(spec)
+
+
+def _require_version_compare(fn):
+    @functools.wraps(fn)
+    def wrapped(self, prospective, spec):
+        if not isinstance(prospective, Version):
+            return False
+        return fn(self, prospective, spec)
+    return wrapped
+
+
+class Specifier(_IndividualSpecifier):
+
+    _regex = re.compile(
+        r"""
+        ^
+        \s*
+        (?P<operator>(~=|==|!=|<=|>=|<|>|===))
+        (?P<version>
+            (?:
+                # The identity operators allow for an escape hatch that will
+                # do an exact string match of the version you wish to install.
+                # This will not be parsed by PEP 440 and we cannot determine
+                # any semantic meaning from it. This operator is discouraged
+                # but included entirely as an escape hatch.
+                (?<====)  # Only match for the identity operator
+                \s*
+                [^\s]*    # We just match everything, except for whitespace
+                          # since we are only testing for strict identity.
+            )
+            |
+            (?:
+                # The (non)equality operators allow for wild card and local
+                # versions to be specified so we have to define these two
+                # operators separately to enable that.
+                (?<===|!=)            # Only match for equals and not equals
+
+                \s*
+                v?
+                (?:[0-9]+!)?          # epoch
+                [0-9]+(?:\.[0-9]+)*   # release
+                (?:                   # pre release
+                    [-_\.]?
+                    (a|b|c|rc|alpha|beta|pre|preview)
+                    [-_\.]?
+                    [0-9]*
+                )?
+                (?:                   # post release
+                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
+                )?
+
+                # You cannot use a wild card and a dev or local version
+                # together so group them with a | and make them optional.
+                (?:
+                    (?:[-_\.]?dev[-_\.]?[0-9]*)?         # dev release
+                    (?:\+[a-z0-9]+(?:[-_\.][a-z0-9]+)*)? # local
+                    |
+                    \.\*  # Wild card syntax of .*
+                )?
+            )
+            |
+            (?:
+                # The compatible operator requires at least two digits in the
+                # release segment.
+                (?<=~=)               # Only match for the compatible operator
+
+                \s*
+                v?
+                (?:[0-9]+!)?          # epoch
+                [0-9]+(?:\.[0-9]+)+   # release  (We have a + instead of a *)
+                (?:                   # pre release
+                    [-_\.]?
+                    (a|b|c|rc|alpha|beta|pre|preview)
+                    [-_\.]?
+                    [0-9]*
+                )?
+                (?:                                   # post release
+                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
+                )?
+                (?:[-_\.]?dev[-_\.]?[0-9]*)?          # dev release
+            )
+            |
+            (?:
+                # All other operators only allow a sub set of what the
+                # (non)equality operators do. Specifically they do not allow
+                # local versions to be specified nor do they allow the prefix
+                # matching wild cards.
+                (?<!==|!=|~=)         # We have special cases for these
+                                      # operators so we want to make sure they
+                                      # don't match here.
+
+                \s*
+                v?
+                (?:[0-9]+!)?          # epoch
+                [0-9]+(?:\.[0-9]+)*   # release
+                (?:                   # pre release
+                    [-_\.]?
+                    (a|b|c|rc|alpha|beta|pre|preview)
+                    [-_\.]?
+                    [0-9]*
+                )?
+                (?:                                   # post release
+                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
+                )?
+                (?:[-_\.]?dev[-_\.]?[0-9]*)?          # dev release
+            )
+        )
+        \s*
+        $
+        """,
+        re.VERBOSE | re.IGNORECASE,
+    )
+
+    _operators = {
+        "~=": "compatible",
+        "==": "equal",
+        "!=": "not_equal",
+        "<=": "less_than_equal",
+        ">=": "greater_than_equal",
+        "<": "less_than",
+        ">": "greater_than",
+        "===": "arbitrary",
+    }
+
+    @_require_version_compare
+    def _compare_compatible(self, prospective, spec):
+        # Compatible releases have an equivalent combination of >= and ==. That
+        # is that ~=2.2 is equivalent to >=2.2,==2.*. This allows us to
+        # implement this in terms of the other specifiers instead of
+        # implementing it ourselves. The only thing we need to do is construct
+        # the other specifiers.
+
+        # We want everything but the last item in the version, but we want to
+        # ignore post and dev releases and we want to treat the pre-release as
+        # it's own separate segment.
+        prefix = ".".join(
+            list(
+                itertools.takewhile(
+                    lambda x: (not x.startswith("post")
+                               and not x.startswith("dev")),
+                    _version_split(spec),
+                )
+            )[:-1]
+        )
+
+        # Add the prefix notation to the end of our string
+        prefix += ".*"
+
+        return (self._get_operator(">=")(prospective, spec)
+                and self._get_operator("==")(prospective, prefix))
+
+    @_require_version_compare
+    def _compare_equal(self, prospective, spec):
+        # We need special logic to handle prefix matching
+        if spec.endswith(".*"):
+            # Split the spec out by dots, and pretend that there is an implicit
+            # dot in between a release segment and a pre-release segment.
+            spec = _version_split(spec[:-2])  # Remove the trailing .*
+
+            # Split the prospective version out by dots, and pretend that there
+            # is an implicit dot in between a release segment and a pre-release
+            # segment.
+            prospective = _version_split(str(prospective))
+
+            # Shorten the prospective version to be the same length as the spec
+            # so that we can determine if the specifier is a prefix of the
+            # prospective version or not.
+            prospective = prospective[:len(spec)]
+
+            # Pad out our two sides with zeros so that they both equal the same
+            # length.
+            spec, prospective = _pad_version(spec, prospective)
+        else:
+            # Convert our spec string into a Version
+            spec = Version(spec)
+
+            # If the specifier does not have a local segment, then we want to
+            # act as if the prospective version also does not have a local
+            # segment.
+            if not spec.local:
+                prospective = Version(prospective.public)
+
+        return prospective == spec
+
+    @_require_version_compare
+    def _compare_not_equal(self, prospective, spec):
+        return not self._compare_equal(prospective, spec)
+
+    @_require_version_compare
+    def _compare_less_than_equal(self, prospective, spec):
+        return prospective <= Version(spec)
+
+    @_require_version_compare
+    def _compare_greater_than_equal(self, prospective, spec):
+        return prospective >= Version(spec)
+
+    @_require_version_compare
+    def _compare_less_than(self, prospective, spec):
+        # Less than are defined as exclusive operators, this implies that
+        # pre-releases do not match for the same series as the spec. This is
+        # implemented by making <V imply !=V.*.
+        return (prospective < Version(spec)
+                and self._get_operator("!=")(prospective, spec + ".*"))
+
+    @_require_version_compare
+    def _compare_greater_than(self, prospective, spec):
+        # Greater than are defined as exclusive operators, this implies that
+        # pre-releases do not match for the same series as the spec. This is
+        # implemented by making >V imply !=V.*.
+        return (prospective > Version(spec)
+                and self._get_operator("!=")(prospective, spec + ".*"))
+
+    def _compare_arbitrary(self, prospective, spec):
+        return str(prospective).lower() == str(spec).lower()
+
+    @property
+    def prereleases(self):
+        # If there is an explicit prereleases set for this, then we'll just
+        # blindly use that.
+        if self._prereleases is not None:
+            return self._prereleases
+
+        # Look at all of our specifiers and determine if they are inclusive
+        # operators, and if they are if they are including an explicit
+        # prerelease.
+        operator, version = self._spec
+        if operator in ["==", ">=", "<=", "~="]:
+            # The == specifier can include a trailing .*, if it does we
+            # want to remove before parsing.
+            if operator == "==" and version.endswith(".*"):
+                version = version[:-2]
+
+            # Parse the version, and if it is a pre-release than this
+            # specifier allows pre-releases.
+            if parse(version).is_prerelease:
+                return True
+
+        return False
+
+    @prereleases.setter
+    def prereleases(self, value):
+        self._prereleases = value
+
+
+_prefix_regex = re.compile(r"^([0-9]+)((?:a|b|c|rc)[0-9]+)$")
+
+
+def _version_split(version):
+    result = []
+    for item in version.split("."):
+        match = _prefix_regex.search(item)
+        if match:
+            result.extend(match.groups())
+        else:
+            result.append(item)
+    return result
+
+
+def _pad_version(left, right):
+    left_split, right_split = [], []
+
+    # Get the release segment of our versions
+    left_split.append(list(itertools.takewhile(lambda x: x.isdigit(), left)))
+    right_split.append(list(itertools.takewhile(lambda x: x.isdigit(), right)))
+
+    # Get the rest of our versions
+    left_split.append(left[len(left_split):])
+    right_split.append(left[len(right_split):])
+
+    # Insert our padding
+    left_split.insert(
+        1,
+        ["0"] * max(0, len(right_split[0]) - len(left_split[0])),
+    )
+    right_split.insert(
+        1,
+        ["0"] * max(0, len(left_split[0]) - len(right_split[0])),
+    )
+
+    return (
+        list(itertools.chain(*left_split)),
+        list(itertools.chain(*right_split)),
+    )
+
+
+class SpecifierSet(BaseSpecifier):
+
+    def __init__(self, specifiers="", prereleases=None):
+        # Split on , to break each indidivual specifier into it's own item, and
+        # strip each item to remove leading/trailing whitespace.
+        specifiers = [s.strip() for s in specifiers.split(",") if s.strip()]
+
+        # Parsed each individual specifier, attempting first to make it a
+        # Specifier and falling back to a LegacySpecifier.
+        parsed = set()
+        for specifier in specifiers:
+            try:
+                parsed.add(Specifier(specifier))
+            except InvalidSpecifier:
+                parsed.add(LegacySpecifier(specifier))
+
+        # Turn our parsed specifiers into a frozen set and save them for later.
+        self._specs = frozenset(parsed)
+
+        # Store our prereleases value so we can use it later to determine if
+        # we accept prereleases or not.
+        self._prereleases = prereleases
+
+    def __repr__(self):
+        pre = (
+            ", prereleases={0!r}".format(self.prereleases)
+            if self._prereleases is not None
+            else ""
+        )
+
+        return "<SpecifierSet({0!r}{1})>".format(str(self), pre)
+
+    def __str__(self):
+        return ",".join(sorted(str(s) for s in self._specs))
+
+    def __hash__(self):
+        return hash(self._specs)
+
+    def __and__(self, other):
+        if isinstance(other, string_types):
+            other = SpecifierSet(other)
+        elif not isinstance(other, SpecifierSet):
+            return NotImplemented
+
+        specifier = SpecifierSet()
+        specifier._specs = frozenset(self._specs | other._specs)
+
+        if self._prereleases is None and other._prereleases is not None:
+            specifier._prereleases = other._prereleases
+        elif self._prereleases is not None and other._prereleases is None:
+            specifier._prereleases = self._prereleases
+        elif self._prereleases == other._prereleases:
+            specifier._prereleases = self._prereleases
+        else:
+            raise ValueError(
+                "Cannot combine SpecifierSets with True and False prerelease "
+                "overrides."
+            )
+
+        return specifier
+
+    def __eq__(self, other):
+        if isinstance(other, string_types):
+            other = SpecifierSet(other)
+        elif isinstance(other, _IndividualSpecifier):
+            other = SpecifierSet(str(other))
+        elif not isinstance(other, SpecifierSet):
+            return NotImplemented
+
+        return self._specs == other._specs
+
+    def __ne__(self, other):
+        if isinstance(other, string_types):
+            other = SpecifierSet(other)
+        elif isinstance(other, _IndividualSpecifier):
+            other = SpecifierSet(str(other))
+        elif not isinstance(other, SpecifierSet):
+            return NotImplemented
+
+        return self._specs != other._specs
+
+    @property
+    def prereleases(self):
+        # If we have been given an explicit prerelease modifier, then we'll
+        # pass that through here.
+        if self._prereleases is not None:
+            return self._prereleases
+
+        # Otherwise we'll see if any of the given specifiers accept
+        # prereleases, if any of them do we'll return True, otherwise False.
+        # Note: The use of any() here means that an empty set of specifiers
+        #       will always return False, this is an explicit design decision.
+        return any(s.prereleases for s in self._specs)
+
+    @prereleases.setter
+    def prereleases(self, value):
+        self._prereleases = value
+
+    def contains(self, item, prereleases=None):
+        # Ensure that our item is a Version or LegacyVersion instance.
+        if not isinstance(item, (LegacyVersion, Version)):
+            item = parse(item)
+
+        # We can determine if we're going to allow pre-releases by looking to
+        # see if any of the underlying items supports them. If none of them do
+        # and this item is a pre-release then we do not allow it and we can
+        # short circuit that here.
+        # Note: This means that 1.0.dev1 would not be contained in something
+        #       like >=1.0.devabc however it would be in >=1.0.debabc,>0.0.dev0
+        if (not (self.prereleases or prereleases)) and item.is_prerelease:
+            return False
+
+        # Determine if we're forcing a prerelease or not, we bypass
+        # self.prereleases here and use self._prereleases because we want to
+        # only take into consideration actual *forced* values. The underlying
+        # specifiers will handle the other logic.
+        # The logic here is: If prereleases is anything but None, we'll just
+        #                    go aheand and continue to use that. However if
+        #                    prereleases is None, then we'll use whatever the
+        #                    value of self._prereleases is as long as it is not
+        #                    None itself.
+        if prereleases is None and self._prereleases is not None:
+            prereleases = self._prereleases
+
+        # We simply dispatch to the underlying specs here to make sure that the
+        # given version is contained within all of them.
+        # Note: This use of all() here means that an empty set of specifiers
+        #       will always return True, this is an explicit design decision.
+        return all(
+            s.contains(item, prereleases=prereleases)
+            for s in self._specs
+        )
+
+    def filter(self, iterable, prereleases=None):
+        # Determine if we're forcing a prerelease or not, we bypass
+        # self.prereleases here and use self._prereleases because we want to
+        # only take into consideration actual *forced* values. The underlying
+        # specifiers will handle the other logic.
+        # The logic here is: If prereleases is anything but None, we'll just
+        #                    go aheand and continue to use that. However if
+        #                    prereleases is None, then we'll use whatever the
+        #                    value of self._prereleases is as long as it is not
+        #                    None itself.
+        if prereleases is None and self._prereleases is not None:
+            prereleases = self._prereleases
+
+        # If we have any specifiers, then we want to wrap our iterable in the
+        # filter method for each one, this will act as a logical AND amongst
+        # each specifier.
+        if self._specs:
+            for spec in self._specs:
+                iterable = spec.filter(iterable, prereleases=prereleases)
+            return iterable
+        # If we do not have any specifiers, then we need to have a rough filter
+        # which will filter out any pre-releases, unless there are no final
+        # releases, and which will filter out LegacyVersion in general.
+        else:
+            filtered = []
+            found_prereleases = []
+
+            for item in iterable:
+                # Ensure that we some kind of Version class for this item.
+                if not isinstance(item, (LegacyVersion, Version)):
+                    parsed_version = parse(item)
+                else:
+                    parsed_version = item
+
+                # Filter out any item which is parsed as a LegacyVersion
+                if isinstance(parsed_version, LegacyVersion):
+                    continue
+
+                # Store any item which is a pre-release for later unless we've
+                # already found a final version or we are accepting prereleases
+                if parsed_version.is_prerelease and not prereleases:
+                    if not filtered:
+                        found_prereleases.append(item)
+                else:
+                    filtered.append(item)
+
+            # If we've found no items except for pre-releases, then we'll go
+            # ahead and use the pre-releases
+            if not filtered and found_prereleases and prereleases is None:
+                return found_prereleases
+
+            return filtered
diff --git a/setuptools/_vendor/packaging/version.py b/setuptools/_vendor/packaging/version.py
new file mode 100644
index 00000000..e76e9607
--- /dev/null
+++ b/setuptools/_vendor/packaging/version.py
@@ -0,0 +1,376 @@
+# Copyright 2014 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
+import collections
+import itertools
+import re
+
+from ._structures import Infinity
+
+
+__all__ = [
+    "parse", "Version", "LegacyVersion", "InvalidVersion",
+]
+
+
+_Version = collections.namedtuple(
+    "_Version",
+    ["epoch", "release", "dev", "pre", "post", "local"],
+)
+
+
+def parse(version):
+    """
+    Parse the given version string and return either a :class:`Version` object
+    or a :class:`LegacyVersion` object depending on if the given version is
+    a valid PEP 440 version or a legacy version.
+    """
+    try:
+        return Version(version)
+    except InvalidVersion:
+        return LegacyVersion(version)
+
+
+class InvalidVersion(ValueError):
+    """
+    An invalid version was found, users should refer to PEP 440.
+    """
+
+
+class _BaseVersion(object):
+
+    def __hash__(self):
+        return hash(self._key)
+
+    def __lt__(self, other):
+        return self._compare(other, lambda s, o: s < o)
+
+    def __le__(self, other):
+        return self._compare(other, lambda s, o: s <= o)
+
+    def __eq__(self, other):
+        return self._compare(other, lambda s, o: s == o)
+
+    def __ge__(self, other):
+        return self._compare(other, lambda s, o: s >= o)
+
+    def __gt__(self, other):
+        return self._compare(other, lambda s, o: s > o)
+
+    def __ne__(self, other):
+        return self._compare(other, lambda s, o: s != o)
+
+    def _compare(self, other, method):
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return method(self._key, other._key)
+
+
+class LegacyVersion(_BaseVersion):
+
+    def __init__(self, version):
+        self._version = str(version)
+        self._key = _legacy_cmpkey(self._version)
+
+    def __str__(self):
+        return self._version
+
+    def __repr__(self):
+        return "<LegacyVersion({0})>".format(repr(str(self)))
+
+    @property
+    def public(self):
+        return self._version
+
+    @property
+    def local(self):
+        return None
+
+    @property
+    def is_prerelease(self):
+        return False
+
+
+_legacy_version_component_re = re.compile(
+    r"(\d+ | [a-z]+ | \.| -)", re.VERBOSE,
+)
+
+_legacy_version_replacement_map = {
+    "pre": "c", "preview": "c", "-": "final-", "rc": "c", "dev": "@",
+}
+
+
+def _parse_version_parts(s):
+    for part in _legacy_version_component_re.split(s):
+        part = _legacy_version_replacement_map.get(part, part)
+
+        if not part or part == ".":
+            continue
+
+        if part[:1] in "0123456789":
+            # pad for numeric comparison
+            yield part.zfill(8)
+        else:
+            yield "*" + part
+
+    # ensure that alpha/beta/candidate are before final
+    yield "*final"
+
+
+def _legacy_cmpkey(version):
+    # We hardcode an epoch of -1 here. A PEP 440 version can only have a epoch
+    # greater than or equal to 0. This will effectively put the LegacyVersion,
+    # which uses the defacto standard originally implemented by setuptools,
+    # as before all PEP 440 versions.
+    epoch = -1
+
+    # This scheme is taken from pkg_resources.parse_version setuptools prior to
+    # it's adoption of the packaging library.
+    parts = []
+    for part in _parse_version_parts(version.lower()):
+        if part.startswith("*"):
+            # remove "-" before a prerelease tag
+            if part < "*final":
+                while parts and parts[-1] == "*final-":
+                    parts.pop()
+
+            # remove trailing zeros from each series of numeric parts
+            while parts and parts[-1] == "00000000":
+                parts.pop()
+
+        parts.append(part)
+    parts = tuple(parts)
+
+    return epoch, parts
+
+
+class Version(_BaseVersion):
+
+    _regex = re.compile(
+        r"""
+        ^
+        \s*
+        v?
+        (?:
+            (?:(?P<epoch>[0-9]+)!)?                           # epoch
+            (?P<release>[0-9]+(?:\.[0-9]+)*)                  # release segment
+            (?P<pre>                                          # pre-release
+                [-_\.]?
+                (?P<pre_l>(a|b|c|rc|alpha|beta|pre|preview))
+                [-_\.]?
+                (?P<pre_n>[0-9]+)?
+            )?
+            (?P<post>                                         # post release
+                (?:-(?P<post_n1>[0-9]+))
+                |
+                (?:
+                    [-_\.]?
+                    (?P<post_l>post|rev|r)
+                    [-_\.]?
+                    (?P<post_n2>[0-9]+)?
+                )
+            )?
+            (?P<dev>                                          # dev release
+                [-_\.]?
+                (?P<dev_l>dev)
+                [-_\.]?
+                (?P<dev_n>[0-9]+)?
+            )?
+        )
+        (?:\+(?P<local>[a-z0-9]+(?:[-_\.][a-z0-9]+)*))?       # local version
+        \s*
+        $
+        """,
+        re.VERBOSE | re.IGNORECASE,
+    )
+
+    def __init__(self, version):
+        # Validate the version and parse it into pieces
+        match = self._regex.search(version)
+        if not match:
+            raise InvalidVersion("Invalid version: '{0}'".format(version))
+
+        # Store the parsed out pieces of the version
+        self._version = _Version(
+            epoch=int(match.group("epoch")) if match.group("epoch") else 0,
+            release=tuple(int(i) for i in match.group("release").split(".")),
+            pre=_parse_letter_version(
+                match.group("pre_l"),
+                match.group("pre_n"),
+            ),
+            post=_parse_letter_version(
+                match.group("post_l"),
+                match.group("post_n1") or match.group("post_n2"),
+            ),
+            dev=_parse_letter_version(
+                match.group("dev_l"),
+                match.group("dev_n"),
+            ),
+            local=_parse_local_version(match.group("local")),
+        )
+
+        # Generate a key which will be used for sorting
+        self._key = _cmpkey(
+            self._version.epoch,
+            self._version.release,
+            self._version.pre,
+            self._version.post,
+            self._version.dev,
+            self._version.local,
+        )
+
+    def __repr__(self):
+        return "<Version({0})>".format(repr(str(self)))
+
+    def __str__(self):
+        parts = []
+
+        # Epoch
+        if self._version.epoch != 0:
+            parts.append("{0}!".format(self._version.epoch))
+
+        # Release segment
+        parts.append(".".join(str(x) for x in self._version.release))
+
+        # Pre-release
+        if self._version.pre is not None:
+            parts.append("".join(str(x) for x in self._version.pre))
+
+        # Post-release
+        if self._version.post is not None:
+            parts.append(".post{0}".format(self._version.post[1]))
+
+        # Development release
+        if self._version.dev is not None:
+            parts.append(".dev{0}".format(self._version.dev[1]))
+
+        # Local version segment
+        if self._version.local is not None:
+            parts.append(
+                "+{0}".format(".".join(str(x) for x in self._version.local))
+            )
+
+        return "".join(parts)
+
+    @property
+    def public(self):
+        return str(self).split("+", 1)[0]
+
+    @property
+    def local(self):
+        version_string = str(self)
+        if "+" in version_string:
+            return version_string.split("+", 1)[1]
+
+    @property
+    def is_prerelease(self):
+        return bool(self._version.dev or self._version.pre)
+
+
+def _parse_letter_version(letter, number):
+    if letter:
+        # We consider there to be an implicit 0 in a pre-release if there is
+        # not a numeral associated with it.
+        if number is None:
+            number = 0
+
+        # We normalize any letters to their lower case form
+        letter = letter.lower()
+
+        # We consider some words to be alternate spellings of other words and
+        # in those cases we want to normalize the spellings to our preferred
+        # spelling.
+        if letter == "alpha":
+            letter = "a"
+        elif letter == "beta":
+            letter = "b"
+        elif letter in ["rc", "pre", "preview"]:
+            letter = "c"
+
+        return letter, int(number)
+    if not letter and number:
+        # We assume if we are given a number, but we are not given a letter
+        # then this is using the implicit post release syntax (e.g. 1.0-1)
+        letter = "post"
+
+        return letter, int(number)
+
+
+_local_version_seperators = re.compile(r"[\._-]")
+
+
+def _parse_local_version(local):
+    """
+    Takes a string like abc.1.twelve and turns it into ("abc", 1, "twelve").
+    """
+    if local is not None:
+        return tuple(
+            part.lower() if not part.isdigit() else int(part)
+            for part in _local_version_seperators.split(local)
+        )
+
+
+def _cmpkey(epoch, release, pre, post, dev, local):
+    # When we compare a release version, we want to compare it with all of the
+    # trailing zeros removed. So we'll use a reverse the list, drop all the now
+    # leading zeros until we come to something non zero, then take the rest
+    # re-reverse it back into the correct order and make it a tuple and use
+    # that for our sorting key.
+    release = tuple(
+        reversed(list(
+            itertools.dropwhile(
+                lambda x: x == 0,
+                reversed(release),
+            )
+        ))
+    )
+
+    # We need to "trick" the sorting algorithm to put 1.0.dev0 before 1.0a0.
+    # We'll do this by abusing the pre segment, but we _only_ want to do this
+    # if there is not a pre or a post segment. If we have one of those then
+    # the normal sorting rules will handle this case correctly.
+    if pre is None and post is None and dev is not None:
+        pre = -Infinity
+    # Versions without a pre-release (except as noted above) should sort after
+    # those with one.
+    elif pre is None:
+        pre = Infinity
+
+    # Versions without a post segment should sort before those with one.
+    if post is None:
+        post = -Infinity
+
+    # Versions without a development segment should sort after those with one.
+    if dev is None:
+        dev = Infinity
+
+    if local is None:
+        # Versions without a local segment should sort before those with one.
+        local = -Infinity
+    else:
+        # Versions with a local segment need that segment parsed to implement
+        # the sorting rules in PEP440.
+        # - Alpha numeric segments sort before numeric segments
+        # - Alpha numeric segments sort lexicographically
+        # - Numeric segments sort numerically
+        # - Shorter versions sort before longer versions when the prefixes
+        #   match exactly
+        local = tuple(
+            (i, "") if isinstance(i, int) else (-Infinity, i)
+            for i in local
+        )
+
+    return epoch, release, pre, post, dev, local
diff --git a/setuptools/_vendor/vendored.txt b/setuptools/_vendor/vendored.txt
new file mode 100644
index 00000000..b86bba00
--- /dev/null
+++ b/setuptools/_vendor/vendored.txt
@@ -0,0 +1 @@
+packaging==14.3
diff --git a/setuptools/command/egg_info.py b/setuptools/command/egg_info.py
index 06764a17..43df87dc 100755
--- a/setuptools/command/egg_info.py
+++ b/setuptools/command/egg_info.py
@@ -10,6 +10,13 @@ import os
 import re
 import sys
 
+try:
+    import packaging.version
+except ImportError:
+    # fallback to vendored version
+    import setuptools._vendor.packaging.version
+    packaging = setuptools._vendor.packaging
+
 from setuptools import Command
 from setuptools.command.sdist import sdist
 from setuptools.compat import basestring, PY3, StringIO
@@ -68,10 +75,15 @@ class egg_info(Command):
         self.vtags = self.tags()
         self.egg_version = self.tagged_version()
 
+        parsed_version = parse_version(self.egg_version)
+
         try:
+            is_version = isinstance(parsed_version, packaging.version.Version)
+            spec = (
+                "%s==%s" if is_version else "%s===%s"
+            )
             list(
-                parse_requirements('%s==%s' % (self.egg_name,
-                                               self.egg_version))
+                parse_requirements(spec % (self.egg_name, self.egg_version))
             )
         except ValueError:
             raise distutils.errors.DistutilsOptionError(
diff --git a/setuptools/dist.py b/setuptools/dist.py
index 6b9d350e..e44796fd 100644
--- a/setuptools/dist.py
+++ b/setuptools/dist.py
@@ -13,11 +13,19 @@ from distutils.core import Distribution as _Distribution
 from distutils.errors import (DistutilsOptionError, DistutilsPlatformError,
     DistutilsSetupError)
 
+try:
+    import packaging.version
+except ImportError:
+    # fallback to vendored version
+    import setuptools._vendor.packaging.version
+    packaging = setuptools._vendor.packaging
+
 from setuptools.depends import Require
 from setuptools.compat import basestring, PY2
 from setuptools import windows_support
 import pkg_resources
 
+
 def _get_unpatched(cls):
     """Protect against re-patching the distutils if reloaded
 
@@ -269,6 +277,27 @@ class Distribution(_Distribution):
             # Some people apparently take "version number" too literally :)
             self.metadata.version = str(self.metadata.version)
 
+        if self.metadata.version is not None:
+            try:
+                ver = packaging.version.Version(self.metadata.version)
+                normalized_version = str(ver)
+                if self.metadata.version != normalized_version:
+                    warnings.warn(
+                        "The version specified requires normalization, "
+                        "consider using '%s' instead of '%s'." % (
+                            normalized_version,
+                            self.metadata.version,
+                        )
+                    )
+                    self.metadata.version = normalized_version
+            except (packaging.version.InvalidVersion, TypeError):
+                warnings.warn(
+                    "The version specified (%r) is an invalid version, this "
+                    "may not work as expected with newer versions of "
+                    "setuptools, pip, and PyPI. Please see PEP 440 for more "
+                    "details." % self.metadata.version
+                )
+
     def parse_command_line(self):
         """Process features after parsing command line options"""
         result = _Distribution.parse_command_line(self)
diff --git a/setuptools/tests/test_egg_info.py b/setuptools/tests/test_egg_info.py
index e803a41e..4c4f9456 100644
--- a/setuptools/tests/test_egg_info.py
+++ b/setuptools/tests/test_egg_info.py
@@ -155,7 +155,7 @@ class TestSvnDummy(environment.ZippedEnvironment):
             infile.close()
             del infile
 
-        self.assertTrue("Version: 0.1.1-r1\n" in read_contents)
+        self.assertTrue("Version: 0.1.1.post1\n" in read_contents)
 
     @skipIf(not test_svn._svn_check, "No SVN to text, in the first place")
     def test_no_tags(self):
diff --git a/setuptools/tests/test_resources.py b/setuptools/tests/test_resources.py
index 3baa3ab1..356e1ed4 100644
--- a/setuptools/tests/test_resources.py
+++ b/setuptools/tests/test_resources.py
@@ -8,6 +8,10 @@ import tempfile
 import shutil
 from unittest import TestCase
 
+import setuptools._vendor.packaging.version
+import setuptools._vendor.packaging.specifiers
+packaging = setuptools._vendor.packaging
+
 import pkg_resources
 from pkg_resources import (parse_requirements, VersionConflict, parse_version,
     Distribution, EntryPoint, Requirement, safe_version, safe_name,
@@ -103,7 +107,7 @@ class DistroTests(TestCase):
     def checkFooPkg(self,d):
         self.assertEqual(d.project_name, "FooPkg")
         self.assertEqual(d.key, "foopkg")
-        self.assertEqual(d.version, "1.3-1")
+        self.assertEqual(d.version, "1.3.post1")
         self.assertEqual(d.py_version, "2.4")
         self.assertEqual(d.platform, "win32")
         self.assertEqual(d.parsed_version, parse_version("1.3-1"))
@@ -120,9 +124,9 @@ class DistroTests(TestCase):
         self.assertEqual(d.platform, None)
 
     def testDistroParse(self):
-        d = dist_from_fn("FooPkg-1.3_1-py2.4-win32.egg")
+        d = dist_from_fn("FooPkg-1.3.post1-py2.4-win32.egg")
         self.checkFooPkg(d)
-        d = dist_from_fn("FooPkg-1.3_1-py2.4-win32.egg-info")
+        d = dist_from_fn("FooPkg-1.3.post1-py2.4-win32.egg-info")
         self.checkFooPkg(d)
 
     def testDistroMetadata(self):
@@ -330,24 +334,15 @@ class RequirementsTests(TestCase):
         self.assertTrue(twist11 not in r)
         self.assertTrue(twist12 in r)
 
-    def testAdvancedContains(self):
-        r, = parse_requirements("Foo>=1.2,<=1.3,==1.9,>2.0,!=2.5,<3.0,==4.5")
-        for v in ('1.2','1.2.2','1.3','1.9','2.0.1','2.3','2.6','3.0c1','4.5'):
-            self.assertTrue(v in r, (v,r))
-        for v in ('1.2c1','1.3.1','1.5','1.9.1','2.0','2.5','3.0','4.0'):
-            self.assertTrue(v not in r, (v,r))
-
     def testOptionsAndHashing(self):
         r1 = Requirement.parse("Twisted[foo,bar]>=1.2")
         r2 = Requirement.parse("Twisted[bar,FOO]>=1.2")
-        r3 = Requirement.parse("Twisted[BAR,FOO]>=1.2.0")
         self.assertEqual(r1,r2)
-        self.assertEqual(r1,r3)
         self.assertEqual(r1.extras, ("foo","bar"))
         self.assertEqual(r2.extras, ("bar","foo"))  # extras are normalized
         self.assertEqual(hash(r1), hash(r2))
         self.assertEqual(
-            hash(r1), hash(("twisted", ((">=",parse_version("1.2")),),
+            hash(r1), hash(("twisted", packaging.specifiers.SpecifierSet(">=1.2"),
                             frozenset(["foo","bar"])))
         )
 
@@ -420,7 +415,7 @@ class ParseTests(TestCase):
         self.assertNotEqual(safe_name("peak.web"), "peak-web")
 
     def testSafeVersion(self):
-        self.assertEqual(safe_version("1.2-1"), "1.2-1")
+        self.assertEqual(safe_version("1.2-1"), "1.2.post1")
         self.assertEqual(safe_version("1.2 alpha"),  "1.2.alpha")
         self.assertEqual(safe_version("2.3.4 20050521"), "2.3.4.20050521")
         self.assertEqual(safe_version("Money$$$Maker"), "Money-Maker")
@@ -454,12 +449,12 @@ class ParseTests(TestCase):
         c('0.4', '0.4.0')
         c('0.4.0.0', '0.4.0')
         c('0.4.0-0', '0.4-0')
-        c('0pl1', '0.0pl1')
+        c('0post1', '0.0post1')
         c('0pre1', '0.0c1')
         c('0.0.0preview1', '0c1')
         c('0.0c1', '0-rc1')
         c('1.2a1', '1.2.a.1')
-        c('1.2...a', '1.2a')
+        c('1.2.a', '1.2a')
 
     def testVersionOrdering(self):
         def c(s1,s2):
@@ -472,16 +467,14 @@ class ParseTests(TestCase):
         c('2.3a1', '2.3')
         c('2.1-1', '2.1-2')
         c('2.1-1', '2.1.1')
-        c('2.1', '2.1pl4')
+        c('2.1', '2.1post4')
         c('2.1a0-20040501', '2.1')
         c('1.1', '02.1')
-        c('A56','B27')
-        c('3.2', '3.2.pl0')
-        c('3.2-1', '3.2pl1')
-        c('3.2pl1', '3.2pl1-1')
+        c('3.2', '3.2.post0')
+        c('3.2post1', '3.2post2')
         c('0.4', '4.0')
         c('0.0.4', '0.4.0')
-        c('0pl1', '0.4pl1')
+        c('0post1', '0.4post1')
         c('2.1.0-rc1','2.1.0')
         c('2.1dev','2.1a0')
 
diff --git a/setuptools/version.py b/setuptools/version.py
index 0ab618ea..4ca9d5df 100644
--- a/setuptools/version.py
+++ b/setuptools/version.py
@@ -1 +1 @@
-__version__ = '7.1'
+__version__ = '8.0'