如何生成所有可能序列？——itertools

假定有3个位置，每个位置的字符取值可能为"A"或"T"，如何输出所有可能的字符串？

import itertools
for seq in itertools.product("AT", repeat=3):
    # seq is a tuple of 3 strings
    # one case in seq is ("A","A","A")
    seq = "".join(seq)
    print(seq)