python - 如何从python中的两个列表生成嵌套列表

Question

我是 python 的新手，我有两个列表：

l1 = ['a','b','c','d']
l2 = ['new']

我想得到这样的新列表

l3 = [('a','new'),('b','new'),('c','new'),('d','new')]

结合这两个列表的最佳方法是什么？

Answer 1

>>> from itertools import product
>>> l1 = ['a','b','c','d']
>>> l2 = ['new']
>>> list(product(l1,l2))
[('a', 'new'), ('b', 'new'), ('c', 'new'), ('d', 'new')]

Answer 2

如果l2总是只有一个元素，则无需使事情过于复杂

l3 = [(x, l2[0]) for x in l1]

Answer 3

请参阅itertools 文档。

特别是，将 product 用于笛卡尔积：

from itertools import product:
l1 = ['a','b','c','d']
l2 = ['new']
# Cast to list for l3 to be a list since product returns a generator
l3 = list(product(l1, l2))  

Answer 4

>>> from itertools import repeat
>>> l1 = ['a','b','c','d']
>>> l2 = ['new']
>>> zip(l1,repeat(*l2))
[('a', 'new'), ('b', 'new'), ('c', 'new'), ('d', 'new')]

Answer 5

您可以简单地使用列表推导而无需任何功能：

l3 = [(x, y) for x in l1 for y in l2]