# HG changeset patch
# User Brian Neal <bgneal@gmail.com>
# Date 1357783913 21600
# Node ID cfb7f28678c7ec572052215ec2da2ef2df2897ee
# Parent  a13c00c0dfe50daa987db88dfb8d0251041b9d07
bisection() wasn't returning the index like it should. Added some simple tests.

diff -r a13c00c0dfe5 -r cfb7f28678c7 ch3ex3.py
--- a/ch3ex3.py	Wed Jan 09 20:09:19 2013 -0600
+++ b/ch3ex3.py	Wed Jan 09 20:11:53 2013 -0600
@@ -24,4 +24,12 @@
             lo = mid + 1
 
     n = lo - 1
-    return a[n] if n >= 0 and a[n] == item else None
+    return n if n >= 0 and a[n] == item else None
+
+
+if __name__ == '__main__':
+    a = [0, 2, 4, 5, 7, 22]
+
+    assert bisection(a, 0) == 0
+    assert bisection(a, 22) == len(a) - 1
+    assert bisection(a, 4) == 2