bpo-39791 native hooks for importlib.resources.files (GH-20576)

* Provide native .files support on SourceFileLoader.

* Add native importlib.resources.files() support to zipimporter. Remove fallback support.

* make regen-all

* 📜🤖 Added by blurb_it.

* Move 'files' into the ResourceReader so it can carry the relevant module name context.

* Create 'importlib.readers' module and add FileReader to it.

* Add zip reader and rely on it for a TraversableResources object on zipimporter.

* Remove TraversableAdapter, no longer needed.

* Update blurb.

* Replace backslashes with forward slashes.

* Incorporate changes from importlib_metadata 2.0, finalizing the interface for extension via get_resource_reader.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>

Lib/zipimport.py

@@ -280,11 +280,8 @@ class zipimporter:
                 return None
         except ZipImportError:
             return None
-        if not _ZipImportResourceReader._registered:
-            from importlib.abc import ResourceReader
-            ResourceReader.register(_ZipImportResourceReader)
-            _ZipImportResourceReader._registered = True
-        return _ZipImportResourceReader(self, fullname)
+        from importlib.readers import ZipReader
+        return ZipReader(self, fullname)
 
 
     def __repr__(self):
@@ -719,74 +716,3 @@ def _get_module_code(self, fullname):
             return code, ispackage, modpath
     else:
         raise ZipImportError(f"can't find module {fullname!r}", name=fullname)
-
-
-class _ZipImportResourceReader:
-    """Private class used to support ZipImport.get_resource_reader().
-
-    This class is allowed to reference all the innards and private parts of
-    the zipimporter.
-    """
-    _registered = False
-
-    def __init__(self, zipimporter, fullname):
-        self.zipimporter = zipimporter
-        self.fullname = fullname
-
-    def open_resource(self, resource):
-        fullname_as_path = self.fullname.replace('.', '/')
-        path = f'{fullname_as_path}/{resource}'
-        from io import BytesIO
-        try:
-            return BytesIO(self.zipimporter.get_data(path))
-        except OSError:
-            raise FileNotFoundError(path)
-
-    def resource_path(self, resource):
-        # All resources are in the zip file, so there is no path to the file.
-        # Raising FileNotFoundError tells the higher level API to extract the
-        # binary data and create a temporary file.
-        raise FileNotFoundError
-
-    def is_resource(self, name):
-        # Maybe we could do better, but if we can get the data, it's a
-        # resource.  Otherwise it isn't.
-        fullname_as_path = self.fullname.replace('.', '/')
-        path = f'{fullname_as_path}/{name}'
-        try:
-            self.zipimporter.get_data(path)
-        except OSError:
-            return False
-        return True
-
-    def contents(self):
-        # This is a bit convoluted, because fullname will be a module path,
-        # but _files is a list of file names relative to the top of the
-        # archive's namespace.  We want to compare file paths to find all the
-        # names of things inside the module represented by fullname.  So we
-        # turn the module path of fullname into a file path relative to the
-        # top of the archive, and then we iterate through _files looking for
-        # names inside that "directory".
-        from pathlib import Path
-        fullname_path = Path(self.zipimporter.get_filename(self.fullname))
-        relative_path = fullname_path.relative_to(self.zipimporter.archive)
-        # Don't forget that fullname names a package, so its path will include
-        # __init__.py, which we want to ignore.
-        assert relative_path.name == '__init__.py'
-        package_path = relative_path.parent
-        subdirs_seen = set()
-        for filename in self.zipimporter._files:
-            try:
-                relative = Path(filename).relative_to(package_path)
-            except ValueError:
-                continue
-            # If the path of the file (which is relative to the top of the zip
-            # namespace), relative to the package given when the resource
-            # reader was created, has a parent, then it's a name in a
-            # subdirectory and thus we skip it.
-            parent_name = relative.parent.name
-            if len(parent_name) == 0:
-                yield relative.name
-            elif parent_name not in subdirs_seen:
-                subdirs_seen.add(parent_name)
-                yield parent_name