Allow EntryPoint to be pickled while still allowing to get the di…

…stribution.
s0undt3ch · Nov 17, 2020 · Nov 17, 2020 · Nov 17, 2020 · Nov 17, 2020 · 2a128848c7e09145e6fdeeb68ed8a58ae44d08f9
commit 2a128848c7e09145e6fdeeb68ed8a58ae44d08f9
diff --git a/Doc/library/importlib.metadata.rst b/Doc/library/importlib.metadata.rst
@@ -76,24 +76,27 @@ Entry points
 
 The ``entry_points()`` function returns a dictionary of all entry points,
 keyed by group.  Entry points are represented by ``EntryPoint`` instances;
-each ``EntryPoint`` has a ``.name``, ``.group``, and ``.value`` attributes and
-a ``.load()`` method to resolve the value.  There are also ``.module``,
-``.attr``, and ``.extras`` attributes for getting the components of the
-``.value`` attribute::
+each ``EntryPoint`` has a ``.name``, ``.group``, ``.value`` and ``.dist``
+attributes and a ``.load()`` method to resolve the value.  There are also
+``.module``, ``.attr``, and ``.extras`` attributes for getting the components of the
+``.value`` attribute and ``.distribution`` to get the ``Distribution`` instance
+from where the ``EntryPoint`` was loaded::
 
     >>> eps = entry_points()  # doctest: +SKIP
     >>> list(eps)  # doctest: +SKIP
     ['console_scripts', 'distutils.commands', 'distutils.setup_keywords', 'egg_info.writers', 'setuptools.installation']
     >>> scripts = eps['console_scripts']  # doctest: +SKIP
     >>> wheel = [ep for ep in scripts if ep.name == 'wheel'][0]  # doctest: +SKIP
     >>> wheel  # doctest: +SKIP
-    EntryPoint(name='wheel', value='wheel.cli:main', group='console_scripts')
+    EntryPoint(name='wheel', value='wheel.cli:main', group='console_scripts', dist='wheel')
     >>> wheel.module  # doctest: +SKIP
     'wheel.cli'
     >>> wheel.attr  # doctest: +SKIP
     'main'
     >>> wheel.extras  # doctest: +SKIP
     []
+    >>> wheel.distributuion  # doctest: +SKIP
+    <importlib.metadata.PathDistribution object at 0x7f6b309fc668>
     >>> main = wheel.load()  # doctest: +SKIP
     >>> main  # doctest: +SKIP
     <function main at 0x103528488>

diff --git a/Lib/importlib/metadata.py b/Lib/importlib/metadata.py
@@ -48,7 +48,7 @@ def name(self):
 
 
 class EntryPoint(
-        collections.namedtuple('EntryPointBase', 'dist name value group')):
+        collections.namedtuple('EntryPointBase', 'name value group dist')):
     """An entry point as defined by Python packaging conventions.
 
     See `the packaging docs on entry points
@@ -77,6 +77,8 @@ class EntryPoint(
     following the attr, and following any extras.
     """
 
+    _distribution = None
+
     def load(self):
         """Load the entry point from its definition. If only a module
         is indicated by the value, return that module. Otherwise,
@@ -102,13 +104,21 @@ def extras(self):
         match = self.pattern.match(self.value)
         return list(re.finditer(r'\w+', match.group('extras') or ''))
 
+    @property
+    def distribution(self):
+        if self._distribution is None:
+            self._distribution = Distribution.from_name(self.dist)
+        return self._distribution
+
     @classmethod
     def _from_config(cls, dist, config):
-        return [
-            cls(dist, name, value, group)
-            for group in config.sections()
-            for name, value in config.items(group)
-            ]
+        eps = []
+        for group in config.sections():
+            for name, value in config.items(group):
+                ep = cls(name, value, group, dist.name)
+                ep._distribution = dist
+                eps.append(ep)
+        return eps
 
     @classmethod
     def _from_text(cls, dist, text):
@@ -131,7 +141,7 @@ def __iter__(self):
     def __reduce__(self):
         return (
             self.__class__,
-            (self.name, self.value, self.group),
+            (self.name, self.value, self.group, self.dist),
             )
 
 

diff --git a/Lib/test/test_importlib/test_main.py b/Lib/test/test_importlib/test_main.py
@@ -70,6 +70,7 @@ def test_resolve_without_attr(self):
             name='ep',
             value='importlib.metadata',
             group='grp',
+            dist='distribution'
             )
         assert ep.load() is importlib.metadata
 
@@ -232,7 +233,7 @@ def test_discovery(self):
 class TestEntryPoints(unittest.TestCase):
     def __init__(self, *args):
         super(TestEntryPoints, self).__init__(*args)
-        self.ep = importlib.metadata.EntryPoint('name', 'value', 'group')
+        self.ep = importlib.metadata.EntryPoint('name', 'value', 'group', 'dist')
 
     def test_entry_point_pickleable(self):
         revived = pickle.loads(pickle.dumps(self.ep))

diff --git a/Lib/test/test_importlib/test_metadata_api.py b/Lib/test/test_importlib/test_metadata_api.py
@@ -55,8 +55,10 @@ def test_entry_points_distribution(self):
         entries = dict(entry_points()['entries'])
         for entry in ("main", "ns:sub"):
             ep = entries[entry]
-            self.assertEqual(ep.dist.name, "distinfo-pkg")
-            self.assertEqual(ep.dist.version, "1.0.0")
+            self.assertIsInstance(ep.distribution, Distribution)
+            dist = Distribution.from_name(ep.dist)
+            self.assertEqual(ep.distribution.name, dist.name)
+            self.assertEqual(ep.distribution.version, dist.version)
 
     def test_metadata_for_this_package(self):
         md = metadata('egginfo-pkg')