Concat的每个元素与第二个列表的每个元素

Question

我有两个清单 ['_ru', '_uk', '_en'], ['1','2','3']

我怎么能得到

['1_ru', '1_uk', '1_en', '2_ru', '2_uk', '2_en', '3_ru', '3_uk', '3_en']

一行？

Answer 1

您可以使用itertools.product获取两个列表的笛卡尔积并加入它们,就像这样

>>> l2, l1 = ['_ru', '_uk', '_en'], ['1','2','3']
>>> from itertools import product
>>> ["".join(items) for items in product(l1, l2)]
['1_ru', '1_uk', '1_en', '2_ru', '2_uk', '2_en', '3_ru', '3_uk', '3_en']

或者在一行中,列表理解

>>> ["{}{}".format(i1, i2) for i1 in l1 for i2 in l2]
['1_ru', '1_uk', '1_en', '2_ru', '2_uk', '2_en', '3_ru', '3_uk', '3_en']

这与为第一个列表中的每个项目迭代第二个列表并累积结果基本相同,就像这样

>>> result = []
>>> for i1 in l1:
...     for i2 in l2:
...         result.append("{}{}".format(i1, i2))
>>> result
['1_ru', '1_uk', '1_en', '2_ru', '2_uk', '2_en', '3_ru', '3_uk', '3_en']