gh-161229: Accept None for globals and locals in __lazy_import__()

Lib/test/test_lazy_import/__init__.py

@@ -770,6 +770,20 @@ def test_dunder_lazy_import_invalid_arguments(self):
             b"TypeError: Item in ``from list'' must be str, not int",
             result.err)
 
+    @support.requires_subprocess()
+    def test_dunder_lazy_import_explicit_none(self):
+        """__lazy_import__ should accept None for globals and locals."""
+        code = textwrap.dedent("""
+            import sys
+            import types
+
+            lazy = __lazy_import__("test.test_lazy_import.data.basic2",
+                                   globals=None, locals=None)
+            assert type(globals()["lazy"]) is types.LazyImportType
+            assert "test.test_lazy_import.data.basic2" not in sys.modules
+        """)
+        assert_python_ok("-c", code)
+
     def test_dunder_lazy_import_builtins(self):
         """__lazy_import__ should use module's __builtins__ for __import__."""
         from test.test_lazy_import.data import dunder_lazy_import_builtins

Misc/NEWS.d/next/Core_and_Builtins/2026-11-03-05-52-49.gh-issue-161229.8pOPOI.rst

@@ -0,0 +1,2 @@
+:func:`!__lazy_import__` now treats ``None`` for *globals* and *locals* the
+same as omitting them, matching its signature.

Python/bltinmodule.c

@@ -312,7 +312,7 @@ builtin___lazy_import___impl(PyObject *module, PyObject *name,
 {
     PyObject *builtins;
     PyThreadState *tstate = PyThreadState_GET();
-    if (globals == NULL) {
+    if (globals == NULL || globals == Py_None) {
         globals = PyEval_GetGlobals();
         if (globals == NULL) {
             PyErr_SetString(PyExc_TypeError,
@@ -321,7 +321,7 @@ builtin___lazy_import___impl(PyObject *module, PyObject *name,
             return NULL;
         }
     }
-    if (locals == NULL) {
+    if (locals == NULL || locals == Py_None) {
         locals = globals;
     }