在 Python 中打印两个列表的组合

Question

我要打印的内容如下，为简单起见，在每个字符串中使用 2 个变量。我认为使用循环有问题，我对 Python 有点陌生。提前致谢！

com0 <-(a) with (1,)

com1 <-(a) with (2,)

com2 <-(a) with (1, 2)

com3 <-(b) with (1,)

com4 <-(b) with (2,)

com5 <-(b) with (1, 2)

com6 <-(a,b) with (1,)

com7 <-(a,b) with (2,)

com8 <-(a,b) with (1, 2)

这是我试过的：

import itertools

i = 0 #v1

j = 0 #v2

v1 = [1, 2]

v2 = ["a","b"]

while j < 2**len(v2):

    for K in range(0, len(v2)+1):

        while i < 2**len(v1):

            for L in range(0, len(v1)+1):

                for subset2 in itertools.combinations(v1, L):

                    for subset1 in itertools.combinations(v2, K):

                        print("com{0} <-{1} with {2}".format(i,subset1,subset2))

                        i+=1

                        j+=1

Answer 1

你不需要这么多循环。只需使用combinations并product从itertoools>>> from itertools import combinations, product>>>&nbsp;>>> v1 = [1, 2]>>> v2 = ["a","b"]>>>&nbsp;>>> all_v1 = [e for i in range(len(v1)) for e in combinations(v1,i+1)]>>> all_v2 = [e for i in range(len(v1)) for e in combinations(v2,i+1)]>>>&nbsp;>>> for i, (x,y) in enumerate(product(all_v2, all_v1)):...&nbsp; &nbsp; &nbsp;print (f'com{i} <-{x} with {y}')...&nbsp;com0 <-('a',) with (1,)com1 <-('a',) with (2,)com2 <-('a',) with (1, 2)com3 <-('b',) with (1,)com4 <-('b',) with (2,)com5 <-('b',) with (1, 2)com6 <-('a', 'b') with (1,)com7 <-('a', 'b') with (2,)com8 <-('a', 'b') with (1, 2)

Answer 2

来自 itertools 的结果product()是两个列表的笛卡尔积。通过使用此函数，您可以避免所有循环：import itertoolsv1 = [1, 2]v2 = ["a","b"]combinations = list(itertools.product(v1, v2))>> [(1, "a"), (1, "b"), (2, "a"), (2, "b")]