Issue #26186: Remove an invalid type check in

importlib.util.LazyLoader.

The class was checking its argument as to whether its implementation
of create_module() came directly from importlib.abc.Loader. The
problem is that the classes coming from imoprtlib.machinery do not
directly inherit from the ABC as they come from _frozen_importlib.
Because the documentation has always said that create_module() was
ignored, the check has simply been removed.

Lib/importlib/abc.py

@@ -4,7 +4,6 @@ from . import _bootstrap_external
 from . import machinery
 try:
     import _frozen_importlib
-#    import _frozen_importlib_external
 except ImportError as exc:
     if exc.name != '_frozen_importlib':
         raise

Lib/importlib/util.py

@@ -263,11 +263,6 @@ class LazyLoader(abc.Loader):
     def __check_eager_loader(loader):
         if not hasattr(loader, 'exec_module'):
             raise TypeError('loader must define exec_module()')
-        elif hasattr(loader.__class__, 'create_module'):
-            if abc.Loader.create_module != loader.__class__.create_module:
-                # Only care if create_module() is overridden in a subclass of
-                # importlib.abc.Loader.
-                raise TypeError('loader cannot define create_module()')
 
     @classmethod
     def factory(cls, loader):

Lib/test/test_importlib/test_lazy.py

@@ -54,6 +54,7 @@ class LazyLoaderTests(unittest.TestCase):
 
     def test_init(self):
         with self.assertRaises(TypeError):
+            # Classes that dono't define exec_module() trigger TypeError.
             util.LazyLoader(object)
 
     def new_module(self, source_code=None):

Misc/NEWS

@@ -76,6 +76,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #26186: Remove an invalid type check in importlib.util.LazyLoader.
+
 - Issue #26367: importlib.__init__() raises RuntimeError like
   builtins.__import__() when ``level`` is specified but without an accompanying
   package specified.