binary search

def binary_search(data,value):

    left=0

    right=len(data)-1

    while left<=right:

        mid=(left+right)//2

        if data[mid]==value:

            return mid

        elif data[mid]<value:

            left=mid+1

        else:

            right=mid+1

    return -1

list02=[10,20,30,40,50,60]

found=binary_search(list02,50)

if found==(-1):

    print("此值在list內找不到")

else:

    print("此值{}在list內找到了".format(list02[found]))