while

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

n = 1
while n <=10:
    if n == 7:
        n = n + 1
        continue
    print(n)
    n = n + 1

2、输出1-100内所有奇数

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

3、输出1-100内所有偶数

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

4、求1-100内所有数的和

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

5、求1-1+3-4+5...99的所有数的和

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

 6、用户登录（三次机会）

count = 0
while count < 3:
    user = input('>>>>>>')
    pwd = input('>>>>>>')
    if user == 'h' and pwd == '123':
        print('登陆成功')
        break
    else:
        print('用户名或密码错误')
    count = count + 1