Deprecate LegacyVersion/LegacySpecifier

CHANGELOG.rst

@@ -4,6 +4,7 @@ Changelog
 *unreleased*
 ~~~~~~~~~~~~
 
+* Deprecate the ``LegacyVersion`` and ``LegacySpecifier`` classes (:issue:`321`)
 * Handle ``OSError`` on non-dynamic executables when attempting to resolve
   the glibc version string.
 

docs/specifiers.rst

@@ -53,10 +53,11 @@ Reference
     This class abstracts handling specifying the dependencies of a project. It
     can be passed a single specifier (``>=3.0``), a comma-separated list of
     specifiers (``>=3.0,!=3.1``), or no specifier at all. Each individual
-    specifier be attempted to be parsed as a PEP 440 specifier
+    specifier will be attempted to be parsed as a PEP 440 specifier
     (:class:`Specifier`) or as a legacy, setuptools style specifier
-    (:class:`LegacySpecifier`). You may combine :class:`SpecifierSet` instances
-    using the ``&`` operator (``SpecifierSet(">2") & SpecifierSet("<4")``).
+    (deprecated :class:`LegacySpecifier`). You may combine
+    :class:`SpecifierSet` instances using the ``&`` operator
+    (``SpecifierSet(">2") & SpecifierSet("<4")``).
 
     Both the membership tests and the combination support using raw strings
     in place of already instantiated objects.
@@ -90,8 +91,8 @@ Reference
     .. method:: contains(version, prereleases=None)
 
         Determines if ``version``, which can be either a version string, a
-        :class:`Version`, or a :class:`LegacyVersion` object, is contained
-        within this set of specifiers.
+        :class:`Version`, or a deprecated :class:`LegacyVersion` object, is
+        contained within this set of specifiers.
 
         This will either match or not match prereleases based on the
         ``prereleases`` parameter. When ``prereleases`` is set to ``None``
@@ -105,15 +106,15 @@ Reference
 
     .. method:: __iter__()
 
-        Returns an iterator over all the underlying :class:`Specifier`
-        (or :class:`LegacySpecifier`) instances in this specifier set.
+        Returns an iterator over all the underlying :class:`Specifier` (or
+        deprecated :class:`LegacySpecifier`) instances in this specifier set.
 
     .. method:: filter(iterable, prereleases=None)
 
         Takes an iterable that can contain version strings, :class:`~.Version`,
-        and :class:`~.LegacyVersion` instances and will then filter it, returning
-        an iterable that contains only items which match the rules of this
-        specifier object.
+        and deprecated :class:`~.LegacyVersion` instances and will then filter
+        it, returning an iterable that contains only items which match the
+        rules of this specifier object.
 
         This method is smarter than just
         ``filter(Specifier().contains, [...])`` because it implements the rule
@@ -170,6 +171,10 @@ Reference
 
 .. class:: LegacySpecifier(specifier, prereleases=None)
 
+    .. deprecated:: 20.5
+
+        Use :class:`Specifier` instead.
+
     This class abstracts the handling of a single legacy, setuptools style
     specifier. It is generally not required to instantiate this manually,
     preferring instead to work with :class:`SpecifierSet`.

docs/version.rst

@@ -51,7 +51,7 @@ Reference
 
     This function takes a version string and will parse it as a
     :class:`Version` if the version is a valid PEP 440 version, otherwise it
-    will parse it as a :class:`LegacyVersion`.
+    will parse it as a deprecated :class:`LegacyVersion`.
 
 
 .. class:: Version(version)
@@ -140,6 +140,10 @@ Reference
 
 .. class:: LegacyVersion(version)
 
+    .. deprecated:: 20.5
+
+        Use :class:`Version` instead.
+
     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`.

packaging/specifiers.py

@@ -7,6 +7,7 @@
 import functools
 import itertools
 import re
+import warnings
 
 from ._compat import string_types, with_metaclass
 from ._typing import TYPE_CHECKING
@@ -275,6 +276,16 @@ class LegacySpecifier(_IndividualSpecifier):
         ">": "greater_than",
     }
 
+    def __init__(self, spec="", prereleases=None):
+        # type: (str, Optional[bool]) -> None
+        super(LegacySpecifier, self).__init__(spec, prereleases)
+
+        warnings.warn(
+            "Creating a LegacyVersion has been deprecated and will be "
+            "removed in the next major release",
+            DeprecationWarning,
+        )
+
     def _coerce_version(self, version):
         # type: (Union[ParsedVersion, str]) -> LegacyVersion
         if not isinstance(version, LegacyVersion):
@@ -307,7 +318,7 @@ def _compare_greater_than(self, prospective, spec):
 
 
 def _require_version_compare(
-    fn  # type: (Callable[[Specifier, ParsedVersion, str], bool])
+    fn,  # type: (Callable[[Specifier, ParsedVersion, str], bool])
 ):
     # type: (...) -> Callable[[Specifier, ParsedVersion, str], bool]
     @functools.wraps(fn)

packaging/version.py

@@ -6,6 +6,7 @@
 import collections
 import itertools
 import re
+import warnings
 
 from ._structures import Infinity, NegativeInfinity
 from ._typing import TYPE_CHECKING
@@ -123,6 +124,12 @@ def __init__(self, version):
         self._version = str(version)
         self._key = _legacy_cmpkey(self._version)
 
+        warnings.warn(
+            "Creating a LegacyVersion has been deprecated and will be "
+            "removed in the next major release",
+            DeprecationWarning,
+        )
+
     def __str__(self):
         # type: () -> str
         return self._version

tests/test_specifiers.py

@@ -5,6 +5,7 @@
 
 import itertools
 import operator
+import warnings
 
 import pytest
 
@@ -632,6 +633,12 @@ def test_iteration(self, spec, expected_items):
 
 
 class TestLegacySpecifier:
+    def test_legacy_specifier_is_deprecated(self):
+        with warnings.catch_warnings(record=True) as w:
+            LegacySpecifier(">=some-legacy-version")
+            assert len(w) == 1
+            assert issubclass(w[0].category, DeprecationWarning)
+
     @pytest.mark.parametrize(
         ("version", "spec", "expected"),
         [

tests/test_version.py

@@ -5,6 +5,7 @@
 
 import itertools
 import operator
+import warnings
 
 import pretend
 import pytest
@@ -780,6 +781,12 @@ def test_micro_version(self):
 
 
 class TestLegacyVersion:
+    def test_legacy_version_is_deprecated(self):
+        with warnings.catch_warnings(record=True) as w:
+            LegacyVersion("some-legacy-version")
+            assert len(w) == 1
+            assert issubclass(w[0].category, DeprecationWarning)
+
     @pytest.mark.parametrize("version", VERSIONS + LEGACY_VERSIONS)
     def test_valid_legacy_versions(self, version):
         LegacyVersion(version)