From ea46d462fcfd7d393b71b14206a5e6d86bf1994b Mon Sep 17 00:00:00 2001
From: Zhongyue Luo <zhongyue.nah@intel.com>
Date: Thu, 31 Jan 2013 14:24:29 +0800
Subject: Fixes 'not in' operator usage

Change-Id: Ibac9853fc72e2452fa5e2b3a493bd03523faabfb
---
 HACKING.rst | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'HACKING.rst')

diff --git a/HACKING.rst b/HACKING.rst
index 7dda11a..3f6a3ed 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -27,6 +27,18 @@ General
     mylist = Foo().list() # OKAY, does not shadow built-in
 
 
+- Use the "not in" operator for collection membership evaluation. Example::
+
+    if not X in Y:  # BAD, hard to understand
+        pass
+
+    if X not in Y:  # OKAY, intuitive
+        pass
+
+    if not (X in Y or X is Z):  # OKAY, still better than all those 'not's
+        pass
+
+
 TODO vs FIXME
 -------------
 
-- 
cgit