https://github.com/python/cpython/commit/15a597e9ba0dd79bf953e181251788782fff6164 commit: 15a597e9ba0dd79bf953e181251788782fff6164 branch: 3.15 author: Miss Islington (bot) <[email protected]> committer: JelleZijlstra <[email protected]> date: 2026-05-13T03:36:32Z summary:
[3.15] gh-149642: Fix interaction between exec and lazy_imports=all (GH-149643) (#149749) gh-149642: Fix interaction between exec and lazy_imports=all (GH-149643) (cherry picked from commit 4087ff859958abc897711b501bb66dc308890ba5) Co-authored-by: Jelle Zijlstra <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2026-05-10-07-42-36.gh-issue-149642.6ZksML.rst M Lib/test/test_lazy_import/__init__.py M Python/ceval.c diff --git a/Lib/test/test_lazy_import/__init__.py b/Lib/test/test_lazy_import/__init__.py index ea534a8ee5b981..5d770eeae07a15 100644 --- a/Lib/test/test_lazy_import/__init__.py +++ b/Lib/test/test_lazy_import/__init__.py @@ -301,6 +301,15 @@ def f(): f() self.assertIn("only allowed at module level", str(cm.exception)) + def test_lazy_import_exec_in_class(self): + """lazy import via exec() inside a class should raise SyntaxError.""" + # exec() inside a class body also has non-module-level locals. + with self.assertRaises(SyntaxError) as cm: + class C: + exec("lazy import json") + + self.assertIn("only allowed at module level", str(cm.exception)) + @support.requires_subprocess() def test_lazy_import_exec_at_module_level(self): """lazy import via exec() at module level should work.""" @@ -352,6 +361,50 @@ def test_eager_import_func(self): f = test.test_lazy_import.data.eager_import_func.f self.assertEqual(type(f()), type(sys)) + def test_exec_import_func(self): + """Implicit lazy imports via exec() inside functions should be eager.""" + sys.set_lazy_imports("all") + + def f(): + exec("import test.test_lazy_import.data.basic2") + + f() + self.assertIn("test.test_lazy_import.data.basic2", sys.modules) + + def test_exec_import_func_with_lazy_modules(self): + """__lazy_modules__ should not make exec() imports lazy inside functions.""" + globals()["__lazy_modules__"] = ["test.test_lazy_import.data.basic2"] + try: + def f(): + exec("import test.test_lazy_import.data.basic2") + + f() + self.assertIn("test.test_lazy_import.data.basic2", sys.modules) + finally: + del globals()["__lazy_modules__"] + + def test_exec_import_class(self): + """Implicit lazy imports via exec() inside classes should be eager.""" + sys.set_lazy_imports("all") + + class C: + exec("import test.test_lazy_import.data.basic2") + + self.assertIsNotNone(C) + self.assertIn("test.test_lazy_import.data.basic2", sys.modules) + + def test_exec_import_class_with_lazy_modules(self): + """__lazy_modules__ should not make exec() imports lazy inside classes.""" + globals()["__lazy_modules__"] = ["test.test_lazy_import.data.basic2"] + try: + class C: + exec("import test.test_lazy_import.data.basic2") + + self.assertIsNotNone(C) + self.assertIn("test.test_lazy_import.data.basic2", sys.modules) + finally: + del globals()["__lazy_modules__"] + class WithStatementTests(unittest.TestCase): """Tests for lazy imports in with statement context.""" diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-05-10-07-42-36.gh-issue-149642.6ZksML.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-05-10-07-42-36.gh-issue-149642.6ZksML.rst new file mode 100644 index 00000000000000..815a084db69d8d --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-05-10-07-42-36.gh-issue-149642.6ZksML.rst @@ -0,0 +1,2 @@ +Allow imports inside ``exec()`` calls within functions under +``PYTHON_LAZY_IMPORTS=all``. diff --git a/Python/ceval.c b/Python/ceval.c index 060e948e6b01c9..a080ae42b93766 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -3059,25 +3059,35 @@ check_lazy_import_compatibility(PyThreadState *tstate, PyObject *globals, return res; } +static int +is_lazy_import_module_level(void) +{ + _PyInterpreterFrame *frame = _PyEval_GetFrame(); + return frame != NULL && frame->f_globals == frame->f_locals; +} + PyObject * _PyEval_LazyImportName(PyThreadState *tstate, PyObject *builtins, PyObject *globals, PyObject *locals, PyObject *name, PyObject *fromlist, PyObject *level, int lazy) { PyObject *res = NULL; + PyImport_LazyImportsMode mode = PyImport_GetLazyImportsMode(); // Check if global policy overrides the local syntax - switch (PyImport_GetLazyImportsMode()) { + switch (mode) { case PyImport_LAZY_NONE: lazy = 0; break; case PyImport_LAZY_ALL: - lazy = 1; + if (!lazy) { + lazy = is_lazy_import_module_level(); + } break; case PyImport_LAZY_NORMAL: break; } - if (!lazy && PyImport_GetLazyImportsMode() != PyImport_LAZY_NONE) { + if (!lazy && mode != PyImport_LAZY_NONE && is_lazy_import_module_level()) { // See if __lazy_modules__ forces this to be lazy. lazy = check_lazy_import_compatibility(tstate, globals, name, level); if (lazy < 0) { _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
