Create 'localize_dist' function to convert stdlib to local versions of Distributions.

Author: jaraco

importlib_metadata/__init__.py

@@ -33,8 +33,9 @@
 from ._compat import (
     NullFinder,
     install,
+    localize_dist,
 )
-from ._functools import method_cache, pass_none
+from ._functools import apply, method_cache, pass_none
 from ._itertools import always_iterable, bucket, unique_everseen
 from ._meta import PackageMetadata, SimplePath
 from .compat import py39, py311
@@ -409,6 +410,7 @@ def locate_file(self, path: str | os.PathLike[str]) -> SimplePath:
         """
 
     @classmethod
+    @apply(localize_dist)
     def from_name(cls, name: str) -> Distribution:
         """Return the Distribution for the given package name.
 
@@ -427,6 +429,7 @@ def from_name(cls, name: str) -> Distribution:
             raise PackageNotFoundError(name)
 
     @classmethod
+    @apply(functools.partial(map, localize_dist))
     def discover(
         cls, *, context: Optional[DistributionFinder.Context] = None, **kwargs
     ) -> Iterable[Distribution]:

importlib_metadata/_compat.py

@@ -1,5 +1,13 @@
+from __future__ import annotations
+
+import importlib.metadata
 import platform
 import sys
+import warnings
+from typing import cast
+
+import importlib_metadata
+
 
 __all__ = ['install', 'NullFinder']
 
@@ -54,3 +62,17 @@ def pypy_partial(val):
     """
     is_pypy = platform.python_implementation() == 'PyPy'
     return val + is_pypy
+
+
+def localize_dist(
+    dist: importlib_metadata.Distribution | importlib.metadata.Distribution,
+) -> importlib_metadata.Distribution:
+    """
+    Ensure dist is an :class:`importlib_metadata.Distribution`.
+    """
+    if isinstance(dist, importlib_metadata.Distribution):
+        return dist
+    if isinstance(dist, importlib.metadata.PathDistribution):
+        return importlib_metadata.PathDistribution(dist._path)
+    warnings.warn(f"Unrecognized distribution subclass {dist.__class__}")
+    return cast(importlib_metadata.Distribution, dist)