bpo-39791: Refresh importlib.metadata from importlib_metadata 1.6.1. (GH-20659) (GH-20661)

* Refresh importlib.metadata from importlib_metadata 1.6.1.

* 📜🤖 Added by blurb_it.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
(cherry picked from commit 161541ab45278df6603dd870113b10f13e4d9e16)

Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>

Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>
diff --git a/Lib/importlib/metadata.py b/Lib/importlib/metadata.py
index 831f593..ffa0cba 100644
--- a/Lib/importlib/metadata.py
+++ b/Lib/importlib/metadata.py
@@ -79,6 +79,16 @@
         return functools.reduce(getattr, attrs, module)
 
     @property
+    def module(self):
+        match = self.pattern.match(self.value)
+        return match.group('module')
+
+    @property
+    def attr(self):
+        match = self.pattern.match(self.value)
+        return match.group('attr')
+
+    @property
     def extras(self):
         match = self.pattern.match(self.value)
         return list(re.finditer(r'\w+', match.group('extras') or ''))
@@ -170,7 +180,7 @@
         """
         for resolver in cls._discover_resolvers():
             dists = resolver(DistributionFinder.Context(name=name))
-            dist = next(dists, None)
+            dist = next(iter(dists), None)
             if dist is not None:
                 return dist
         else:
@@ -213,6 +223,17 @@
             )
         return filter(None, declared)
 
+    @classmethod
+    def _local(cls, root='.'):
+        from pep517 import build, meta
+        system = build.compat_system(root)
+        builder = functools.partial(
+            meta.build,
+            source_dir=root,
+            system=system,
+            )
+        return PathDistribution(zipfile.Path(meta.build_as_zip(builder)))
+
     @property
     def metadata(self):
         """Return the parsed metadata for this Distribution.
@@ -391,7 +412,7 @@
 
     def __init__(self, root):
         self.root = root
-        self.base = os.path.basename(root).lower()
+        self.base = os.path.basename(self.root).lower()
 
     def joinpath(self, child):
         return pathlib.Path(self.root, child)
@@ -408,8 +429,8 @@
         names = zip_path.root.namelist()
         self.joinpath = zip_path.joinpath
 
-        return (
-            posixpath.split(child)[0]
+        return dict.fromkeys(
+            child.split(posixpath.sep, 1)[0]
             for child in names
             )
 
@@ -475,7 +496,6 @@
             )
 
 
-
 class PathDistribution(Distribution):
     def __init__(self, path):
         """Construct a distribution from a path to the metadata directory.
diff --git a/Lib/test/test_importlib/fixtures.py b/Lib/test/test_importlib/fixtures.py
index d923cec..b25febb 100644
--- a/Lib/test/test_importlib/fixtures.py
+++ b/Lib/test/test_importlib/fixtures.py
@@ -161,6 +161,21 @@
         build_files(EggInfoFile.files, prefix=self.site_dir)
 
 
+class LocalPackage:
+    files = {
+        "setup.py": """
+            import setuptools
+            setuptools.setup(name="local-pkg", version="2.0.1")
+            """,
+        }
+
+    def setUp(self):
+        self.fixtures = contextlib.ExitStack()
+        self.addCleanup(self.fixtures.close)
+        self.fixtures.enter_context(tempdir_as_cwd())
+        build_files(self.files)
+
+
 def build_files(file_defs, prefix=pathlib.Path()):
     """Build a set of files/directories, as described by the
 
diff --git a/Lib/test/test_importlib/test_main.py b/Lib/test/test_importlib/test_main.py
index 42a7999..7b18c3d 100644
--- a/Lib/test/test_importlib/test_main.py
+++ b/Lib/test/test_importlib/test_main.py
@@ -246,3 +246,19 @@
         """
         with self.assertRaises(Exception):
             json.dumps(self.ep)
+
+    def test_module(self):
+        assert self.ep.module == 'value'
+
+    def test_attr(self):
+        assert self.ep.attr is None
+
+
+class FileSystem(fixtures.OnSysPath, fixtures.SiteDir, unittest.TestCase):
+    def test_unicode_dir_on_sys_path(self):
+        """
+        Ensure a Unicode subdirectory of a directory on sys.path
+        does not crash.
+        """
+        fixtures.build_files({'☃': {}}, prefix=self.site_dir)
+        list(distributions())
diff --git a/Lib/test/test_importlib/test_zip.py b/Lib/test/test_importlib/test_zip.py
index fa87cd7..a5399c1 100644
--- a/Lib/test/test_importlib/test_zip.py
+++ b/Lib/test/test_importlib/test_zip.py
@@ -3,9 +3,10 @@
 
 from contextlib import ExitStack
 from importlib.metadata import (
-    distribution, entry_points, files, PackageNotFoundError, version,
+    distribution, entry_points, files, PackageNotFoundError,
+    version, distributions,
 )
-from importlib.resources import path
+from importlib import resources
 
 from test.support import requires_zlib
 
@@ -14,15 +15,19 @@
 class TestZip(unittest.TestCase):
     root = 'test.test_importlib.data'
 
+    def _fixture_on_path(self, filename):
+        pkg_file = resources.files(self.root).joinpath(filename)
+        file = self.resources.enter_context(resources.as_file(pkg_file))
+        assert file.name.startswith('example-'), file.name
+        sys.path.insert(0, str(file))
+        self.resources.callback(sys.path.pop, 0)
+
     def setUp(self):
         # Find the path to the example-*.whl so we can add it to the front of
         # sys.path, where we'll then try to find the metadata thereof.
         self.resources = ExitStack()
         self.addCleanup(self.resources.close)
-        wheel = self.resources.enter_context(
-            path(self.root, 'example-21.12-py3-none-any.whl'))
-        sys.path.insert(0, str(wheel))
-        self.resources.callback(sys.path.pop, 0)
+        self._fixture_on_path('example-21.12-py3-none-any.whl')
 
     def test_zip_version(self):
         self.assertEqual(version('example'), '21.12')
@@ -49,6 +54,10 @@
             path = str(file.dist.locate_file(file))
             assert '.whl/' in path, path
 
+    def test_one_distribution(self):
+        dists = list(distributions(path=sys.path[:1]))
+        assert len(dists) == 1
+
 
 @requires_zlib()
 class TestEgg(TestZip):
@@ -57,10 +66,7 @@
         # sys.path, where we'll then try to find the metadata thereof.
         self.resources = ExitStack()
         self.addCleanup(self.resources.close)
-        egg = self.resources.enter_context(
-            path(self.root, 'example-21.12-py3.6.egg'))
-        sys.path.insert(0, str(egg))
-        self.resources.callback(sys.path.pop, 0)
+        self._fixture_on_path('example-21.12-py3.6.egg')
 
     def test_files(self):
         for file in files('example'):