Time for an 2014 update…

Task/Binary-search/Python/binary-search-4.py

@@ -0,0 +1,6 @@
+from bisect import bisect_left
+
+def binary_search(a, x, lo=0, hi=None):   # can't use a to specify default for hi
+    hi = hi if hi is not None else len(a) # hi defaults to len(a)
+    pos = bisect_left(a,x,lo,hi)          # find insertion position
+    return (pos if pos != hi and a[pos] == x else -1) # don't walk off the end

Task/Binary-search/Python/binary-search-5.py

@@ -0,0 +1,12 @@
+def binary_search(l, value):
+    low = 0
+    high = len(l)-1
+    while low + 1 < high:
+        mid = (low+high)//2
+        if l[mid] > value:
+            high = mid
+        elif l[mid] < value:
+            low = mid
+        else:
+            return mid
+    return high if abs(l[high] - value) < abs(l[low] - value) else low