udacity sample binary search

Udacity_binarysearch.py

"""You're going to write a binary search function.
You should use an iterative approach - meaning
using loops.
Your function should take two inputs:
a Python list to search through, and the value
you're searching for.
Assume the list only has distinct elements,
meaning there are no repeated values, and 
elements are in a strictly increasing order.
Return the index of value, or -1 if the value
doesn't exist in the list."""

current_idx = 0
def binary_search(input_array, value):
    lower = 0
    upper = len (input_array)-1

    while (upper >= lower):
        mid_idx = (upper+lower)//2
        if input_array[mid_idx]< value:
            lower = mid_idx+1
        elif input_array[mid_idx]==value:
            return mid_idx
        else:
            if lower == upper:
                return -1
            upper = mid_idx




test_list = [1,3,9,11,15,19,29]
test_val1 = 25
test_val2 = 15
print (binary_search(test_list, test_val1))
print (binary_search(test_list, test_val2))
print("haha")