python(三)——while语句

while死循环

 #!/usr/bin/env python
 #-*- coding:utf8 -*-

 import time
 while 1 == 1:
     print('Ok',time.time())

import time

count = 0
while count < 10:
    print('Ok',time.time())
    count = count + 1

print('')

# 输出1-100内所有的偶数
count = 1
while count <= 100:
    if count % 2 == 0:
        print(count)
    count = count + 1

# 求 1-2+3-4+5-6...99所有数的和
count = 1
sum = 0
while count < 100:
    temp = count
    if count % 2 == 0:
        temp = -count
    sum += temp
    count = count + 1

print(sum)

# while 输出1 2 3 4 5 6   7 8 9

n = 0
while n < 10:
    if n == 7:
        pass
    else:
        print(n)
    n = n + 1

#!/usr/bin/env python
#-*- coding:utf8 -*-

# 允许用户登录三次
# 变量
count = 0
while count < 3:
    n1 = input('请输入用户名：')
    n2 = input('请输入用户名密码：')

    if n1 == 'root' and n2 == 'root123':
        print('登录成功')
        count = 3
    else:
        print('登录失败')

    count = count + 1