python多线程：排列组合

import threading
import time

list = [chr(i) for i in range(ord('a'), ord('z') + 1)] + [chr(i) for i in range(ord('0'), ord('9') + 1)] + ['_']

print('程序开始时间：', time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(int(time.time()))))
start = time.time()


def thread(head):
    for lst1 in list:
        for lst2 in list:
            for lst3 in list:
                for lst4 in list:
                    for lst5 in list:
                        print(head + lst1 + lst2 + lst3 + lst4 + lst5, '\n')
    end = time.time()
    print('程序结束时间：', time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(int(time.time()))))
    print('程序用时:', end - start, 's')


if __name__ == '__main__':
    for i in range(37):
        threading.Thread(target=thread, args=(list[i],)).start()