gh-109653: Improve enum import time by avoiding import of functools (GH-109789)

AlexWaygood · web-flow · commit 51863b7d6ea1 · 2023-09-23T11:31:17.000-07:00
diff --git a/Lib/enum.py b/Lib/enum.py
@@ -1,8 +1,6 @@
 import sys
 import builtins as bltns
 from types import MappingProxyType, DynamicClassAttribute
-from operator import or_ as _or_
-from functools import reduce
 
 
 __all__ = [
@@ -1884,7 +1882,8 @@ def __call__(self, enumeration):
                     missed = [v for v in values if v not in member_values]
                     if missed:
                         missing_names.append(name)
-                        missing_value |= reduce(_or_, missed)
+                        for val in missed:
+                            missing_value |= val
                 if missing_names:
                     if len(missing_names) == 1:
                         alias = 'alias %s is missing' % missing_names[0]
diff --git a/Misc/NEWS.d/next/Library/2023-09-23-12-47-45.gh-issue-109653.9wZBfs.rst b/Misc/NEWS.d/next/Library/2023-09-23-12-47-45.gh-issue-109653.9wZBfs.rst
@@ -0,0 +1 @@
+Reduce the import time of :mod:`enum` by over 50%. Patch by Alex Waygood.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Reduce the import time of :mod:`enum` by over 50%. Patch by Alex Waygood.