a simple binary search

binary_searches.py

def binary_search(array, target):
    lower = 0
    upper = len(array)
    while lower < upper:
        x = lower + (upper - lower) // 2
        value = array[x]
        if target == value:
            return x
        elif target > value:
            if lower == x:
                break
        elif target < value:
            upper = x