3 python基础教程之常用入门程序

1，打印输出 1～100

count = 1

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

 

2，打印输出1+2+3……+100

1 count = 1
2 sum = 0
3 while count < 101:
4     sum = sum + count   
5     count += 1
6 print(sum)

 

3，打印输出1～100中的奇数

1 count = 1
2 while count < 101:
3     if count % 2 == 1:
4         print(count)
5     else:
6         pass
7     count += 1

 

4，打印输出1～100中的偶数

1 count = 0
2 while count < 101:
3     if count % 2 == 0:
4         print(count)
5     else:
6         pass
7     count += 1

 

5，计算1-2+3-4……99

 

count = 0
sum = 0
while count < 100:
    if count % 2 == 1:
        sum = sum + count
    else:
        sum = sum - count
    count += 1
print(sum)

 

6，设计程序允许重试三次登陆

count = 1 #定义一个变量，用来存储重试次数
while count <= 3: #最大重试次数为3次
    username = input('请输入您的用户名：')
    password = input('请输入您的密码：')
    if username == 'python' and password == 123: #给定一组用户名&密码
        print ('seccuss!') #登陆成功
    else: #登录失败
        print ('登陆失败，请重试')
        count += 1
print('你是不是忘记了？')

 

posted @ 2019-06-04 08:43  JMay  阅读(236)  评论(0)  编辑  收藏  举报