python-random

import  random
import string

#从a-zA-Z0-9中生成指定数量的随机字符
ran_str = ''.join(random.sample(string.ascii_letters + string.digits,18))
print(ran_str)

# 多个字符中生成指定数量的随机字符
r1 = ''.join(random.sample('abcd!@#$%0123456789ABCDEFGHIJKLMNOPQRST',3))
print(r1)

# 
print(random.choice(["water","fire","gasoline"]))

参考 https://www.runoob.com/note/40199