itertools产品功能背后的概念 [英] The Concept Behind itertools's product Function

问题描述

所以基本上我想了解itertools中product()函数的概念.我的意思是收益率和收益率有什么区别.而且该代码可以缩短吗?

so basically i want to understand the concept of product() function in itertools. i mean what is the different between yield and return. And can this code be shorten down anyway.

    def product1(*args, **kwds):
        pools = map(tuple, args) * kwds.get('repeat', 1)
        n = len(pools)
        if n == 0:
            yield ()
            return
        if any(len(pool) == 0 for pool in pools):
            return
        indices = [0] * n
        yield tuple(pool[i] for pool, i in zip(pools, indices))
        while 1:
            for i in reversed(range(n)):  # right to left
                if indices[i] == len(pools[i]) - 1:
                    continue
                indices[i] += 1
                for j in range(i+1, n):
                    indices[j] = 0
                yield tuple(pool[i] for pool, i in zip(pools, indices))
                break
            else:
                return

推荐答案

此代码应能完成工作:

bytes = [i for i in range(2**(n))]
AB= []
for obj in bytes:
    t = str(bin(obj))[2:]
    t= '0'*(n-len(t)) + t
    AB.append(t.replace('0','A').replace('1','B'))

n是想要的字符串大小

n being the string size wanted

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