From bbb4367b55ead1a0322d86b568c6c4607f539d3e Mon Sep 17 00:00:00 2001
From: Barney Gale <barney.gale@gmail.com>
Date: Sat, 25 Nov 2023 17:41:05 +0000
Subject: [PATCH] GH-77621: Delay some imports from pathlib (#112244)

Import `contextlib`, `glob` and `re` only as required.

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
---
 Lib/pathlib.py                                     | 14 +++++++++-----
 .../2023-11-21-02-58-14.gh-issue-77621.MYv5XS.rst  |  2 ++
 2 files changed, 11 insertions(+), 5 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2023-11-21-02-58-14.gh-issue-77621.MYv5XS.rst

diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 32ccf818b15..0e01099d490 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -5,14 +5,11 @@
 operating systems.
 """
 
-import contextlib
 import functools
-import glob
 import io
 import ntpath
 import os
 import posixpath
-import re
 import sys
 import warnings
 from _collections_abc import Sequence
@@ -75,17 +72,23 @@ def _is_case_sensitive(pathmod):
 # Globbing helpers
 #
 
+re = glob = None
+
 
 @functools.lru_cache(maxsize=256)
 def _compile_pattern(pat, sep, case_sensitive):
     """Compile given glob pattern to a re.Pattern object (observing case
     sensitivity)."""
+    global re, glob
+    if re is None:
+        import re, glob
+
     flags = re.NOFLAG if case_sensitive else re.IGNORECASE
     regex = glob.translate(pat, recursive=True, include_hidden=True, seps=sep)
     # The string representation of an empty path is a single dot ('.'). Empty
     # paths shouldn't match wildcards, so we consume it with an atomic group.
     regex = r'(\.\Z)?+' + regex
-    return re.compile(regex, flags).match
+    return re.compile(regex, flags=flags).match
 
 
 def _select_children(parent_paths, dir_only, follow_symlinks, match):
@@ -981,7 +984,8 @@ def iterdir(self):
     def _scandir(self):
         # Emulate os.scandir(), which returns an object that can be used as a
         # context manager. This method is called by walk() and glob().
-        return contextlib.nullcontext(self.iterdir())
+        from contextlib import nullcontext
+        return nullcontext(self.iterdir())
 
     def _make_child_relpath(self, name):
         path_str = str(self)
diff --git a/Misc/NEWS.d/next/Library/2023-11-21-02-58-14.gh-issue-77621.MYv5XS.rst b/Misc/NEWS.d/next/Library/2023-11-21-02-58-14.gh-issue-77621.MYv5XS.rst
new file mode 100644
index 00000000000..f3e6efc389a
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-11-21-02-58-14.gh-issue-77621.MYv5XS.rst
@@ -0,0 +1,2 @@
+Slightly improve the import time of the :mod:`pathlib` module by deferring
+some imports. Patch by Barney Gale.