pythongh-121735: Allow to list package resources inside zip by module…

… name

which is inside that package

Lib/importlib/resources/readers.py

@@ -35,7 +35,9 @@ def files(self):
 class ZipReader(abc.TraversableResources):
     def __init__(self, loader, module):
         _, _, name = module.rpartition('.')
-        self.prefix = loader.prefix.replace('\\', '/') + name + '/'
+        self.prefix = loader.prefix.replace('\\', '/') + name
+        if not self.prefix.endswith('/'):
+            self.prefix += '/'
         self.archive = loader.archive
 
     def open_resource(self, resource):

Lib/test/test_importlib/resources/data04/package/resource.txt

@@ -0,0 +1 @@
+data

Lib/test/test_importlib/resources/test_resource.py

@@ -134,6 +134,27 @@ def test_unrelated_contents(self):
         )
 
 
+class ResourceFromZipsTest04(util.ZipSetupBase, unittest.TestCase):
+    ZIP_MODULE = 'data04'
+
+    def test_package_resources(self):
+        self.assertEqual(
+            names(resources.files('data04.package')),
+            {'__init__.py', 'module.py', 'resource.txt'},
+        )
+
+    def test_resources_of_module_inside_package(self):
+        """
+        A module inside a package can have resources found adjacent to the module.
+        """
+        package_files = resources.files('data04.package.module')
+        self.assertEqual(
+            names(package_files),
+            {'__init__.py', 'module.py', 'resource.txt'},
+        )
+        self.assertEqual(package_files.joinpath('resource.txt').read_text(), 'data\n')
+
+
 class DeletingZipsTest(util.ZipSetupBase, unittest.TestCase):
     """Having accessed resources in a zip file should not keep an open
     reference to the zip.

Lib/zipimport.py

@@ -256,18 +256,22 @@ def load_module(self, fullname):
 
 
     def get_resource_reader(self, fullname):
-        """Return the ResourceReader for a package in a zip file.
+        """Return the ResourceReader for a package/module in a zip file.
 
-        If 'fullname' is a package within the zip file, return the
+        If 'fullname' is a package or a module within a package within the zip file, return the
         'ResourceReader' object for the package.  Otherwise return None.
         """
         try:
-            if not self.is_package(fullname):
+            if self.is_package(fullname):
+                package = fullname
+            elif self.is_package("."):
+                package = "."
+            else:
                 return None
         except ZipImportError:
             return None
         from importlib.readers import ZipReader
-        return ZipReader(self, fullname)
+        return ZipReader(self, package)
 
 
     def _get_files(self):
@@ -307,7 +311,7 @@ def __repr__(self):
 # Given a module name, return the potential file path in the
 # archive (without extension).
 def _get_module_path(self, fullname):
-    return self.prefix + fullname.rpartition('.')[2]
+    return (self.prefix + fullname.rpartition('.')[2]).rstrip(path_sep)
 
 # Does this path represent a directory?
 def _is_dir(self, path):