Added binary search in python

Added binary search in python using an iterative approach

Author: pushpit-J19

Searching Algorithms/binary_search.py

@@ -0,0 +1,35 @@
+# BINARY SEARCH 
+
+# It is a searching algorithm which is more efficient than linear search. It can find an element if present in O(log(n)) time complexity.
+# For this algorithm to work, the array should be in sorted order
+# it returns the position of the element in the array
+
+
+def binary_search (arr, item):
+    """The binary_Search function takes input the sorted list of elements and the item to be searched
+        and returns the position of the item, if found in the list, else it returns -1 """
+    beg, end = 0, len(arr)-1
+    mid = (beg+end)//2
+
+    while beg<=end:
+        mid = (beg+end)//2
+        if arr[mid] == item :
+            return mid
+        elif arr[mid] > item:
+            end = mid-1
+        elif arr[mid] < item:
+            beg = mid+1
+    return -1                   # return -1 if the element is not present in the array
+
+
+
+## DRIVER CODE
+
+test_arr = [1,2,3,4,5]      # this should be a sorted array
+test_item = 2               # this is the item to be searched
+
+ans = binary_search(test_arr, test_item)
+if ans != -1 :
+    print(f"Element found at index position {ans}")
+else:
+    print("Element is not present in array")