GH-119169: Speed up os.walk(topdown=False)#119186
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Handle errors from `os.scandir()` and `ScandirIterator` similarly, which lets us loop over directory entries with `for`. In top-down mode, call `os.path.join()` at most once per iteration.
barneygale added performance 
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vstinner commented May 20, 2024
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barneygale commented May 23, 2024
#119473 fixes the test failure. |
barneygale changed the title os.walk()os.[f]walk()barneygale added a commit to barneygale/cpython that referenced this pull request Jul 6, 2024
When `os.walk()` traverses into subdirectories in top-down mode, call `os.path.join()` once to add a trailing slash, and use string concatenation thereafter to generate child paths.
barneygale changed the title os.[f]walk()os.walk()barneygale added a commit to barneygale/cpython that referenced this pull request Jul 6, 2024
Handle errors from `os.scandir()` and `ScandirIterator` similarly, which lets us loop over directory entries with `for`.
barneygale changed the title os.walk()os.walk(topdown=False)barneygale added a commit to barneygale/cpython that referenced this pull request Jul 8, 2024
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barneygale commented Jul 8, 2024
Closing because reversing sibling traversal order isn't kosher - see discussion on #119473. |
encukou added a commit to barneygale/cpython that referenced this pull request Sep 2, 2025
encukou pushed a commit that referenced this pull request Sep 3, 2025
GH-119186: Slightly speed up `os.walk(topdown=True)` When `os.walk()` traverses into subdirectories in top-down mode, call `os.path.join()` once to add a trailing slash, and use string concatenation thereafter to generate child paths.
lkollar pushed a commit to lkollar/cpython that referenced this pull request Sep 9, 2025
…121431) pythonGH-119186: Slightly speed up `os.walk(topdown=True)` When `os.walk()` traverses into subdirectories in top-down mode, call `os.path.join()` once to add a trailing slash, and use string concatenation thereafter to generate child paths.
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Add entries to the stack while iterating over
os.scandir()results, rather than afterwards.os.walk()#119169