[알고리즘] 이진탐색 Python

def binary_search(arr, target):
    start = 0
    end = len(arr)-1
    while start<=end:
        mid = (start+end)//2
        if arr[mid]==target:
            return mid+1
        elif arr[mid]>target:
            end = mid - 1
        else:
            start = mid + 1
    return 0