import random
b="想"
c="不想"
d=input("请输入想不想指定长度:")
if d==b:
    a=int(input("请输入指定的验证码长度:"))
elif d==c:
    a=4
else:
    print("无效输入")
def yanzhengma(a):

    for i in range(1,a+1):
        i=random.randint(1,9)
        print(i,end="")
yanzhengma(a)