循环并合并以创建新列表

Question

做以下事情的最有效方法是什么？

A = ["A","B","C"]
B = [range(19,21)]

清单结果：

C = ["A19", "B19", "C19", "A20", "B20", "C20"] 

非常感谢！

Answer 1

itertools.product 也可以使用：

from itertools import product

A = ["A","B","C"]
C = [a + str(n) for n, a in product(range(19, 21), A)]

请注意，有多种方法可以将字符串（a）和数字格式化n为单个字符串：

a + str(n)
"{}{}".format(a, n)
f"{a}{n}"  # for python >= 3.6