while循环练习

Posted 2021-03-06 xiaozhen522

1，使用while循环输入1 2 3 4 5 6   8 9

n = 1
while n <= 9:
    if n == 7:
        pass
    else:
        print(n)
    n += 1

2，求1-100的所有数的和

sum = 0
num = 1
while num <= 100:
    sum += num
    num += 1
print(sum)

3，输出1-100内的所有奇数

num = 1
while num <= 100:
    if num % 2 != 0:
        print(num)
    num += 1

4，输出1-100内的所有偶数

num = 1
while num <= 100:
    if num % 2 == 0:
        print(num)
    num += 1

5，求1-2+3-4+5-6.。。99的所有数的和

sum = 0
num = 1
while num < 100:
    if num % 2 == 0:
        sum -= num
    else:
        sum += num
    num += 1
print(sum)

6，用户登录（三次机会重试）

username = "123456"
passward = "123456"
n = 3
while n > 0:
    n -= 1
    user_name = input("请输入用户名")
    pass_ward = input("请输入密码")
    if user_name == user_name and passward == pass_ward:
        print("登录成功")
        break
    else:
        if n != 0:
            print("登陆失败，用户名和密码不匹配请验证后再次尝试，你还有" + str(n) + "次机会！")
        else:
            print("你的账户已锁定，请与管理员联系！")