Python语言:Day9练习题及其答案

1.使用while循环输出1,2,3,4,5,6, 8,9,10

#!/usr/bin/python3

n = 1
while n <= 10:
    if n != 7:
        print(n)
    else:
        pass
    n += 1

2.求1-100的所有数之和

#!/usr/bin/python3

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

3.输出1—100内所有的奇数

#!/usr/bin/python3

n = 1
while n <= 100:
    if n % 2 != 0:
        print(n)
    else:
        pass
    n += 1

4.输出1—100内所有的偶数

#!/usr/bin/python3

n = 1
while n <= 100:
    if n % 2 == 0:
        print(n)
    else:
        pass
    n += 1

　

5.求1-2+3-4+5…99的所有数的和

#!/usr/bin/python3

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

　　

6.用户登录，三次重试机会

#!/usr/bin/python3

user_name = "admin"
pwd = "123456"
num = 1

while True:
    n1 = input("用户名:")
    n2 = input("密码:")
    if n1 == user_name and n2 == pwd:
        print("登陆成功!")
        break
    else:
        num += 1
        if num == 4:
            print("3次用户名或者密码均有误!退出程序.")
            break