gh-92525: make inspect.getfile PEP 420 compliant

Author: carlbordum

Lib/inspect.py

@@ -898,6 +898,9 @@ def getfile(object):
     if ismodule(object):
         if getattr(object, '__file__', None):
             return object.__file__
+        if getattr(object, '__path__', None):
+            # Implicit namespace package. See PEP 420.
+            return object.__path__[0]
         raise TypeError('{!r} is a built-in module'.format(object))
     if isclass(object):
         if hasattr(object, '__module__'):

Lib/test/test_inspect.py

@@ -620,6 +620,12 @@ def __repr__(self):
         with self.assertRaises(TypeError):
             inspect.getfile(er)
 
+    def test_getfile_implicit_namespace_package(self):
+        import test_importlib.namespace_pkgs.module_and_namespace_package as pkg
+        path = inspect.getfile(pkg)
+        self.assertIn("test_importlib/namespace_pkgs/module_and_namespace_package", path)
+        self.assertNotIn("built-in", path)
+
     def test_getmodule_recursion(self):
         from types import ModuleType
         name = '__inspect_dummy'

Misc/NEWS.d/next/Library/2022-05-11-17-53-59.gh-issue-92525.YkK50p.rst

@@ -0,0 +1 @@
+Make ``inspect.getfile`` understand PEP 420 implicit namespace packages