From ea90b032a016122e7871e91c5210f3b4e68768b4 Mon Sep 17 00:00:00 2001
From: Daniel Hollas <daniel.hollas@bristol.ac.uk>
Date: Mon, 2 Mar 2026 21:39:07 +0000
Subject: [PATCH] gh-117865: Speedup import of `inspect` module (#144756)

Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
---
 Lib/inspect.py                                           | 8 ++++----
 Lib/test/test_inspect/test_inspect.py                    | 9 +++++++++
 .../2026-02-12-17-56-17.gh-issue-117865.jE1ema.rst       | 1 +
 3 files changed, 14 insertions(+), 4 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2026-02-12-17-56-17.gh-issue-117865.jE1ema.rst

diff --git a/Lib/inspect.py b/Lib/inspect.py
index 5d8ebb3dd540..dfc5503dee53 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -153,9 +153,9 @@ import importlib.machinery
 import itertools
 import linecache
 import os
-import re
+lazy import re
 import sys
-import tokenize
+lazy import tokenize
 import token
 import types
 import functools
@@ -163,9 +163,9 @@ import builtins
 from keyword import iskeyword
 from operator import attrgetter
 from collections import namedtuple, OrderedDict
-from weakref import ref as make_weakref
+from _weakref import ref as make_weakref
 
-# Create constants for the compiler flags in Include/code.h
+# Create constants for the compiler flags in Include/cpython/code.h
 # We try to get them from dis to avoid duplication
 mod_dict = globals()
 for k, v in dis.COMPILER_FLAG_NAMES.items():
diff --git a/Lib/test/test_inspect/test_inspect.py b/Lib/test/test_inspect/test_inspect.py
index 4ad32c649ea8..68ea62f565d8 100644
--- a/Lib/test/test_inspect/test_inspect.py
+++ b/Lib/test/test_inspect/test_inspect.py
@@ -173,6 +173,15 @@ class custom_descriptor:
         return self.func.__get__(instance, owner)
 
 
+class TestImportTime(unittest.TestCase):
+
+    @cpython_only
+    def test_lazy_import(self):
+        import_helper.ensure_lazy_imports(
+            "inspect", {"re", "tokenize"}
+        )
+
+
 class TestPredicates(IsTestBase):
 
     def test_excluding_predicates(self):
diff --git a/Misc/NEWS.d/next/Library/2026-02-12-17-56-17.gh-issue-117865.jE1ema.rst b/Misc/NEWS.d/next/Library/2026-02-12-17-56-17.gh-issue-117865.jE1ema.rst
new file mode 100644
index 000000000000..f45f6682869e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-02-12-17-56-17.gh-issue-117865.jE1ema.rst
@@ -0,0 +1 @@
+Reduce the import time of :mod:`inspect` module by ~20%.
-- 
2.47.3