From: Raymond Hettinger <rhettinger@users.noreply.github.com>
Date: Tue, 5 Sep 2017 16:40:44 +0000 (-0700)
Subject: Conceptually, roots is a set.  Also searching it as a set is a tiny bit faster (... 
X-Git-Tag: v3.7.0a1~149
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=15ce0bee973596f02983f39e1a1b172b91e9cdda;p=python

Conceptually, roots is a set.  Also searching it as a set is a tiny bit faster (#3338)
---

diff --git a/Lib/functools.py b/Lib/functools.py
index 0873f20715..23ad160930 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -193,7 +193,7 @@ _convert = {
 def total_ordering(cls):
     """Class decorator that fills in missing ordering methods"""
     # Find user-defined comparisons (not those inherited from object).
-    roots = [op for op in _convert if getattr(cls, op, None) is not getattr(object, op, None)]
+    roots = {op for op in _convert if getattr(cls, op, None) is not getattr(object, op, None)}
     if not roots:
         raise ValueError('must define at least one ordering operation: < > <= >=')
     root = max(roots)       # prefer __lt__ to __le__ to __gt__ to __ge__