def binary_search(arr , low , high , x):

    if high >= low:

        mid = (high + low) // 2

        if arr[ mid ] == x:

            return mid

        elif arr[ mid ] > x:

            return binary_search(arr , low , mid -1 , x)

        else:

            return binary_search(arr , mid+1 , high , x)

    else:

        return -1

arr=[ 2 , 3 , 4 , 10 , 40 ]

x=10

result=binary_search(arr , 0 , len(arr)-1 , x)

if result != -1:

    print("Element is present at index", str(result))

else:

    print("Element is not present in array")


-----------------------------------------------------------------

-----------------------------------------------------------------

output:

  Element is present at index 3