指定字符和长度，组合出各种字符串

import itertools as its
words = "12ab" #可选择的字符
r =its.product(words,repeat=8)  #组成8位字符串
dic = open("pwd.txt","a")      #存储为wifi密码字典
#wifi密码完成换行，并写入txt文档
for i in r:
    dic.write("".join(i))
    dic.write("".join("\n"))
dic.close()