有趣的python警长

1.问题描述：

请用python实现推断小偷是谁？

2.上代码：

for thief in ["a", "b", "c", "d"]:
    sum = (thief != "a") + (thief == "c") + (thief == "d") + (thief != "d")
    if sum == 3:

        print((thief != "a"))
        print((thief != "a")+(thief == "c"))
        print((thief != "a")+(thief == "c")+ (thief == "d"))
        print("小偷是：%s" % thief)

3，执行结果：