python 二分法查找

# 给定一个排好序（升序）的列表与待查找的关键字，成功则返回其索引，失败则返回-1。

def search(list, key):
    left = 0     # 左边界
    right = len(list) - 1   # 右边界
    while left <= right:
        mid = (left + right) // 2  # 取得中间索引
        if key > list[mid]:
            left = mid + 1
        elif key < list[mid]:
            right = mid - 1
        else:
            return mid
    else:
        return -1

list = [2, 5, 13, 21, 26, 33, 37]
print(search(list, 5))