如何打破Python中的嵌套循环? [英] How to break nested for loop in Python?

问题描述

我想知道如何从这样的循环中退出:

I wonder how to get out from loop like this:

for a in range(95):
    for b in range(95):
        for c in range(95):
            for d in range(95):
                ...
                do some computings
                ...
                if condition:
                    task completed

任务完成后，所有循环和计算将继续.它们必须被破坏，但我不知道如何-任务完成"之后的单个break语句将仅在最内层的for循环结束，但是它将被多次调用-因此我们一无所获.

After task is completed all loops and computings are continued. They have to be broke but I don't know how - single break statement after "task completed" will end only innermost for loop but it will be invoked again multiple times - so we gain nothing.

在C语言中，我会执行a = b = c = d = 95，但在python中则行不通.当然，我可以改用while循环，但是然后我必须使用X + = 1语句，这看起来很糟糕.

In C I would do a=b=c=d=95 but in python that wouldn't work. Of course I can use while loop instead but then I have to use X+=1 statements and it would look awful.

有帮助吗?

Any help?

关于循环: 我用它使用蛮力破解了一个4字符的密码.这不是真正的目的-仅用于测试.

About the loop: I use it to break a 4-char password using brute-force. It isn't a real purpose - used only for tests.

推荐答案

使用itertools产品:

Using itertools product:

from itertools import product
for a, b, c, d in product(range(95), range(95), range(95), range(95)):
    print a, b, c, d
    if a == 1: break

更短的版本，感谢Ashwini:

Shorter version, thanks Ashwini:

for a, b, c, d in product(range(95), repeat=4):
    print a, b, c, d
    if a == 1: break

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