added binary search in python

Binary Search/hannahkriegler.py

@@ -0,0 +1,20 @@
+def main(array, target):
+    l = 0
+    r = len(array)-1
+    binary_search(array,target,l,r)
+
+
+def binary_search(array,target,low,high):
+    if high < low :
+        print("search was unsuccesful")
+        return
+    mid = (low + high) // 2
+    if array[mid] > target:
+        binary_search(array,target,low,mid-1)
+    elif array[mid] < target:
+            binary_search(array,target,mid+1,high)
+    else :
+        print("index of target is " + str(mid))
+
+
+main([1,3,4,6,7,8,12],12)