Day1：Python基础While循环

1、循环打印

while True:
    print("就是听歌，我们不一样")
    print("在人间")

2、判断退出

count = 1
sum = 0

while count <= 100:
    sum = sum + count
    count = count + 1

print(sum)

count = 1
flag = True

while flag:
    print(count)
    count = count + 1
    if count > 100:
        flag = False

3、Break退出

print("111")
while True:
    print("111")
    print(333)
    break
    print(444)
print("abc")

count = 1
while True:
    count = count + 1
    print(count)
    if count > 100:
        break

4、continue退出循环返回程序重新执行

count = 1
print("333")
while count <= 20:
    print(count)
    continue
    count = count + 1

 5、While else示例（while被break打断不走Else;如果While没被break打断，就执行Else）

count = 0
while count <= 5:
    count += 1
    if count == 3:
       break
    print("Loop", count)

else:
    print("循环正常执行结束～～～～")

 

作业一：打印1～100

count = 1
while True:
    print(count)
    count = count + 1
    if count > 100 :
        break

作业二：求1～100的和

count = 1
sum = 0
while count < 101:
    sum = sum + count
    count = count + 1
print(sum)

作业三：输出1～·100 之间的基数

i = 0
while i < 100:
    i = i + 1
    num = i%2
    if num  == 1:
        print(i)

 作业四：三次密码登录错误退出

# -*- encoding:utf-8 -*-

i = 1
Password = "Abcd1234"

while i <= 3:

    PW = input("请输入你的密码：")
    if PW == Password:
        print("密码输入正确，欢迎登录～～～")
        break
    else:
        num = 3 - i
        if num == 0:
            print("三次尝试结束，请退出，谢谢！")
        else:
            print("密码错误，你还有%s次机会"%(num))
            i = i + 1