###一直循环不会停止,只要1=1判断为真
import time ##time详细时间模块 while 1==1: print(‘ok‘,time.time())
####while循环可以停止的,当不满足判断条件。
import time a = 10 while a < 20: print(‘ok‘,time.time()) a = a + 2 #######当循环到a+2将要等于20的前一个循环时,循环停止,开始输出下面的it is end.... print(‘it is end....‘)
###输出a的循环值
import time a = 10 while a < 20: print(a) a = a + 2 #######当循环到a+2等于或大于20的时候,循环停止,开始输出下面的it is end.... print(‘it is end....‘)
###使用while循环输入1-10 无数字7
a = 1 while a < 11: if a == 7: pass else: print (a) a = a + 1 print(‘end.....‘)
####求1-100所有的奇数
a = 1 while a < 100: print(a) a = a + 2 print(‘所有的奇数....‘)
####求1-100所有的的偶数
a = 2 while a < 100: print(a) a = a + 2 print(‘所有的奇数....‘)
####求1-100所有数的和
n = 1 s = 0 while n < 101: s = s + n n = n + 1 print(s)
####用户登录(三次机会重试),输入错误退出登录。
count = 0 while count < 3: user = input(‘用户名:‘) pwd = input(‘密码‘) if user == ‘eddy‘ and pwd == ‘123‘: print(‘欢迎光临‘) break ###输入正确就会终止循环 else: print(‘用户名密码或错误‘) count = count + 1