python基础循环语句练习

1、使用while循环输入 1 2 3 4 5 6     8 9 10

n = 1
while n < 11:
    if n == 7:
        pass
    else:
        print(n)
    n = n + 1

2、求1-100的所有数的和

n = 1
s = 0
while n < 101:
    s = s + n
    n = n + 1
print(s)

3、输出 1-100 内的所有奇数

n = 1
while n < 101:
    temp = n % 2
    if temp == 1:
        print(n)
    else:
        pass
    n = n + 1

4、输出 1-100 内的所有偶数

n = 1
while n < 101:
    temp = n % 2
    if temp == 0:
        print(n)
    else:
        pass
    n = n + 1

5、求1-2+3-4+5 ... 99的所有数的和

n = 1
s = 0
while n < 101:
    temp = n % 2
    if temp == 0:
        s = s - n
    else:
        s = s + n
    n = n + 1
print(s)

6、死循环

while 1 == 1:
    print('你好')

7、用户登陆（三次机会重试）

count = 0
while count < 3:
    user = input('>>>')
    pwd = input('>>>')
    if user == 'alex' and pwd == '':
        print('欢迎登陆')
        break
    else:
        print('用户名或者密码错误')
    count = count + 1