练习作业1

一、使用while循环输入 1 2 3 4 5 6 _ 7 8 9 1

count = 1
while count < 11:
    if count == 7:
        print(' ')
    else:
        print(count)
    count += 1

二、求1-100所以自然数之和

x = 1
s = 0
while x < 101:
    s = s + x
    x += 1
print(s)

三、输出1-100所以奇数

count = 1
while count < 101:
    if count % 2 == 1:
        print(count)
    count += 1

四、输出1-100所以偶数

count = 1
while count < 101:
    if count % 2 == 0:
        print(count)
    count += 1

五、求1-2+3-4+5...99的结果

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

六、用户登录（三次机会重试）

i = 0
while i < 3:
    username = input('请输入账号：')
    password = int(input('请输入密码：'))
    if username == '我爱你' and password == 123:
        print('登陆成功')
    else:
        print('登录失败，请重新输入账号密码')
    i += 1