gh-117648: Improve performance of os.join (#117654)

nineteendo · eendebakpt · web-flow · commit 99852d9e65ae · 2024-04-09T10:27:14.000+02:00
Replace map() with a method call in the loop body.

Co-authored-by: Pieter Eendebak &lt;pieter.eendebak@gmail.com&gt;
diff --git a/Lib/ntpath.py b/Lib/ntpath.py
@@ -111,7 +111,7 @@ def join(path, *paths):
         if not paths:
             path[:0] + sep  #23780: Ensure compatible data type even if p is null.
         result_drive, result_root, result_path = splitroot(path)
-        for p in map(os.fspath, paths):
+        for p in paths:
             p_drive, p_root, p_path = splitroot(p)
             if p_root:
                 # Second path is absolute
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
@@ -79,7 +79,8 @@ def join(a, *p):
     try:
         if not p:
             path[:0] + sep  #23780: Ensure compatible data type even if p is null.
-        for b in map(os.fspath, p):
+        for b in p:
+            b = os.fspath(b)
             if b.startswith(sep):
                 path = b
             elif not path or path.endswith(sep):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-04-08-20-26-15.gh-issue-117648.NzVEa7.rst b/Misc/NEWS.d/next/Core and Builtins/2024-04-08-20-26-15.gh-issue-117648.NzVEa7.rst
@@ -0,0 +1 @@
+Speedup :func:`os.path.join` by up to 6% on Windows.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Speedup :func:`os.path.join` by up to 6% on Windows.