perf: 10% faster stripping zeros (#1058)

henryiii · web-flow · commit 716beb1c0a5d · 2026-01-14T15:41:05.000-05:00
* perf: try simpler zeros

Signed-off-by: Henry Schreiner &lt;henryfs@princeton.edu&gt;

* perf: use int, smaller diff

Signed-off-by: Henry Schreiner &lt;henryfs@princeton.edu&gt;

* perf: avoid slice if nothing changes

Signed-off-by: Henry Schreiner &lt;henryfs@princeton.edu&gt;

---------

Signed-off-by: Henry Schreiner &lt;henryfs@princeton.edu&gt;
diff --git a/src/packaging/version.py b/src/packaging/version.py
@@ -622,12 +622,13 @@ def release(self) -> tuple[int, ...]:
         >>> _TrimmedRelease('0.0').release
         (0,)
         """
-        # Unlike _strip_trailing_zeros, this leaves one 0.
+        # This leaves one 0.
         rel = super().release
-        i = len(rel)
+        len_release = len(rel)
+        i = len_release
         while i > 1 and rel[i - 1] == 0:
             i -= 1
-        return rel[:i]
+        return rel if i == len_release else rel[:i]
 
 
 def _parse_letter_version(
@@ -669,17 +670,6 @@ def _parse_local_version(local: str | None) -> LocalType | None:
     return None
 
 
-def _strip_trailing_zeros(release: tuple[int, ...]) -> tuple[int, ...]:
-    # We want to strip trailing zeros from a tuple of values. This starts
-    # from the end and returns as soon as it finds a non-zero value. When
-    # reading a lot of versions, this is a fairly hot function, so not using
-    # enumerate/reversed, which is slightly slower.
-    for i in range(len(release) - 1, -1, -1):
-        if release[i] != 0:
-            return release[: i + 1]
-    return ()
-
-
 def _cmpkey(
     epoch: int,
     release: tuple[int, ...],
@@ -690,7 +680,11 @@ def _cmpkey(
 ) -> CmpKey:
     # When we compare a release version, we want to compare it with all of the
     # trailing zeros removed. We will use this for our sorting key.
-    _release = _strip_trailing_zeros(release)
+    len_release = len(release)
+    i = len_release
+    while i and release[i - 1] == 0:
+        i -= 1
+    _release = release if i == len_release else release[:i]
 
     # We need to "trick" the sorting algorithm to put 1.0.dev0 before 1.0a0.
     # We'll do this by abusing the pre segment, but we _only_ want to do this
