From 3b95934e0585762661269d41b5a5d79f1b9c2244 Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Thu, 3 Jun 2010 21:21:03 +0000
Subject: [PATCH] use a set for membership testing

---
 Lib/site.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/site.py b/Lib/site.py
index cbf3325166..9865cc940e 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -276,12 +276,12 @@ def getsitepackages():
     environment, and will return a list of full paths.
     """
     sitepackages = []
-    seen = []
+    seen = set()
 
     for prefix in PREFIXES:
         if not prefix or prefix in seen:
             continue
-        seen.append(prefix)
+        seen.add(prefix)
 
         if sys.platform in ('os2emx', 'riscos'):
             sitepackages.append(os.path.join(prefix, "Lib", "site-packages"))
-- 
2.50.1