binary_search.py

def binari_search (list,item):
    low = 0
    high = len(list)-1
    while low <= high:
        mid = (low+high)//2
        guess = list[mid]
        if guess == item:
            return guess
        if guess> item:
            high = mid -1
        else:
            low = mid+1
    return None
list = ["a",'b','c',"d",'e','f',"g",'h']
item = 'f'

i = binari_search(list,item)
print(i)