Address review

Author: vstinner

Lib/test/test_faulthandler.py

@@ -388,12 +388,11 @@ def test_disable(self):
 
     @skip_segfault_on_android
     def test_dump_ext_modules(self):
-        # Disable sys.stdlib_module_names
+        # Don't filter stdlib module names: disable sys.stdlib_module_names
         code = """
             import faulthandler
             import sys
             import math
-            # Don't filter stdlib module names
             sys.stdlib_module_names = frozenset()
             faulthandler.enable()
             faulthandler._sigsegv()
@@ -418,8 +417,7 @@ def test_dump_ext_modules(self):
             """
         stderr, exitcode = self.get_output(code)
         stderr = '\n'.join(stderr)
-        match = re.search(r'^Extension modules:', stderr, re.MULTILINE)
-        self.assertIsNone(match)
+        self.assertNotIn('Extension modules:', stderr)
 
     def test_is_enabled(self):
         orig_stderr = sys.stderr

Misc/NEWS.d/next/Library/2026-01-30-13-23-06.gh-issue-140824.J1OCrC.rst

@@ -1,3 +1,2 @@
 When :mod:`faulthandler` dumps the list of third-party extension modules,
-ignore ``math.integer`` sub-module since ``math`` package is part of
-:data:`sys.stdlib_module_names`. Patch by Victor Stinner.
+ignore sub-modules of stdlib packages. Patch by Victor Stinner.

Python/pylifecycle.c

@@ -3405,7 +3405,8 @@ _Py_DumpExtensionModules(int fd, PyInterpreterState *interp)
                     }
                     assert(key_len > len);
 
-                    // Ignore "math.integer" if key starts with "math."
+                    // Ignore sub-modules of stdlib packages. For example,
+                    // ignore "math.integer" if key starts with "math.".
                     Py_UCS4 ch = PyUnicode_ReadChar(key, len);
                     if (ch == '.') {
                         is_stdlib_ext = 1;