From: Raymond Hettinger <python@rcn.com>
Date: Wed, 21 Aug 2002 02:22:08 +0000 (+0000)
Subject: Fast size check for sub/super set tests
X-Git-Tag: v2.3c1~4375
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=43db0d6a2c5d57c9cd713928f73b993add965b82;p=thirdparty%2FPython%2Fcpython.git

Fast size check for sub/super set tests
---

diff --git a/Lib/sets.py b/Lib/sets.py
index c678bb449437..7b15aa5a0124 100644
--- a/Lib/sets.py
+++ b/Lib/sets.py
@@ -239,6 +239,8 @@ class BaseSet(object):
     def issubset(self, other):
         """Report whether another set contains this set."""
         self._binary_sanity_check(other)
+        if len(self) > len(other):  # Fast check for obvious cases
+            return False
         for elt in self:
             if elt not in other:
                 return False
@@ -247,6 +249,8 @@ class BaseSet(object):
     def issuperset(self, other):
         """Report whether this set contains another set."""
         self._binary_sanity_check(other)
+        if len(self) < len(other):  # Fast check for obvious cases
+            return False
         for elt in other:
             if elt not in self:
                 return False