added binary_search algo

binary_search.py

@@ -0,0 +1,34 @@
+# Binary Search in python
+
+
+def binarySearch(array, x, low, high):
+
+    if high >= low:
+
+        mid = low + (high - low)//2
+
+        # If found at mid, then return it
+        if array[mid] == x:
+            return mid
+
+        # Search the left half
+        elif array[mid] > x:
+            return binarySearch(array, x, low, mid-1)
+
+        # Search the right half
+        else:
+            return binarySearch(array, x, mid + 1, high)
+
+    else:
+        return -1
+
+
+array = [3, 4, 5, 6, 7, 8, 9]
+x = 4
+
+result = binarySearch(array, x, 0, len(array)-1)
+
+if result != -1:
+    print("Element is present at index " + str(result))
+else:
+    print("Not found")