PEP 440 Implementation

.coveragerc

@@ -1,2 +1,3 @@
 [run]
-branch = True
+branch = True
+omit = packaging/_compat.py

docs/index.rst

@@ -6,12 +6,26 @@ Core utilities for Python packages
 
 Installation
 ------------
+
 You can install packaging with ``pip``:
 
 .. code-block:: console
 
     $ pip install packaging
 
+
+API
+---
+
+.. toctree::
+    :maxdepth: 1
+
+    version
+
+
+Project
+-------
+
 .. toctree::
     :maxdepth: 2
 

docs/version.rst

@@ -0,0 +1,144 @@
+Version Handling
+================
+
+.. currentmodule:: packaging.version
+
+A core requirement of dealing with packages is the ability to work with
+versions. `PEP 440`_ defines the standard version scheme for Python packages
+which has been implemented by this module.
+
+Usage
+-----
+
+.. doctest::
+
+    >>> from packaging.version import Version, Specifier
+    >>> v1 = Version("1.0a5")
+    >>> v2 = Version("1.0")
+    >>> v1
+    <Version('1.0a5')>
+    >>> v2
+    <Version('1.0')>
+    >>> v1 < v2
+    True
+    >>> v1.is_prerelease
+    True
+    >>> v2.is_prerelease
+    False
+    >>> Version("french toast")
+    Traceback (most recent call last):
+        ...
+    InvalidVersion: Invalid version: 'french toast'
+    >>> spec1 = Specifier("~=1.0")
+    >>> spec1
+    <Specifier('~=1.0')>
+    >>> spec2 = Specifier(">=1.0")
+    >>> spec2
+    <Specifier('>=1.0')>
+    >>> # We can combine specifiers
+    >>> combined_spec = spec1 & spec2
+    >>> combined_spec
+    <Specifier('>=1.0,~=1.0')>
+    >>> # We can also implicitly combine a string specifier
+    >>> combined_spec &= "!=1.1"
+    >>> combined_spec
+    <Specifier('!=1.1,>=1.0,~=1.0')>
+    >>> # We can check a version object to see if it falls within a specifier
+    >>> v1 in combined_spec
+    False
+    >>> v2 in combined_spec
+    True
+    >>> # We can even do the same with a string based version
+    >>> "1.4" in combined_spec
+    True
+
+
+Reference
+---------
+
+.. class:: Version(version)
+
+    This class abstracts handling of a project's versions. It implements the
+    scheme defined in `PEP 440`_. A :class:`Version` instance is comparison
+    aware and can be compared and sorted using the standard Python interfaces.
+
+    :param str version: The string representation of a version which will be
+                        parsed and normalized before use.
+    :raises InvalidVersion: If the ``version`` does not conform to PEP 440 in
+                            any way then this exception will be raised.
+
+    .. attribute:: public
+
+        A string representing the public version portion of this ``Version()``.
+
+    .. attribute:: local
+
+        A string representing the local version portion of this ``Version()``
+        if it has one, or ``None`` otherwise.
+
+    .. attribute:: is_prerelease
+
+        A boolean value indicating whether this :class:`Version` instance
+        represents a prerelease or a final release.
+
+
+.. class:: LegacyVersion(version)
+
+    This class abstracts handling of a project's versions if they are not
+    compatible with the scheme defined in `PEP 440`_. It implements a similar
+    interface to that of :class:`Version` however it is considered unorderable
+    and many of the comparison types are not implemented.
+
+    :param str version: The string representation of a version which will be
+                        used as is.
+
+    .. attribute:: public
+
+        A string representing the public version portion of this
+        :class:`LegacyVersion`. This will always be the entire version string.
+
+    .. attribute:: local
+
+        This will always be ``None`` since without `PEP 440`_ we do not have
+        the concept of a local version. It exists primarily to allow a
+        :class:`LegacyVersion` to be used as a stand in for a :class:`Version`.
+
+    .. attribute:: is_prerelease
+
+        A boolean value indicating whether this :class:`LegacyVersion`
+        represents a prerelease or a final release. Since without `PEP 440`_
+        there is no concept of pre or final releases this will always be
+        `False` and exists for compatibility with :class:`Version`.
+
+
+.. class:: Specifier(specifier)
+
+    This class abstracts handling of specifying the dependencies of a project.
+    It implements the scheme defined in `PEP 440`_. You can test membership
+    of a particular version within a set of specifiers in a :class:`Specifier`
+    instance by using the standard ``in`` operator (e.g.
+    ``Version("2.0") in Specifier("==2.0")``). You may also combine Specifier
+    instances using the ``&`` operator (``Specifier(">2") & Specifier(">3")``).
+
+    Both the membership test and the combination supports using raw strings
+    in place of already instantiated objects.
+
+    :param str specifier: The string representation of a specifier which will
+                          be parsed and normalized before use.
+    :raises InvalidSpecifier: If the ``specifier`` does not conform to PEP 440
+                              in any way then this exception will be raised.
+
+
+.. class:: InvalidVersion
+
+    Raised when attempting to create a :class:`Version` with a version string
+    that does not conform to `PEP 440`_.
+
+
+.. class:: InvalidSpecifier
+
+    Raised when attempting to create a :class:`Specifier` with a specifier
+    string that does not conform to `PEP 440`_.
+
+
+.. _`PEP 440`: https://www.python.org/dev/peps/pep-0440/

packaging/_compat.py

@@ -0,0 +1,27 @@
+# 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,

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()