python学习之老男孩python全栈第九期_day001作业

1、使用while循环输入 1 2 3 4 5 6     8 9 10

 count = 0
 while count <= 9:
     count += 1
     if count == 7:continue
     print(count)

或：

 # 把7换成空格
 count = 0
 while count < 10:
     count += 1
     if count == 7:
         print(' ')
     else:
         print(count)
 # 不输入空格
 count = 0
 while count < 10:
     count += 1
     if count == 7:continue
     print(count)
 # 用pass
 count = 0
 while count <= 9:
     count += 1
     if count == 7:
         pass              #直接跳过
     else:
         print(count)

2、求1-100的所有数的和

 count = 0
 sum = 0
 while count < 100:
     count += 1
     sum = sum + count
 print(sum)

3、输出 1-100 内的所有奇数

 count = 0
 while count < 100:
     count += 1
     if count % 2 == 0:continue
     print(count)

或：

# 第一种方法
count = 1
while count < 101:
    print(count)
    count += 2
# 第二种方法
count = 1
while count < 101:
    if count % 2 == 1:
        print(count)
    count += 1

4、输出 1-100 内的所有偶数

 count = 0
 while count < 100:
     count += 1
     if count % 2 == 1:continue
     print(count)

5、求1-2+3-4+5 ... 99的所有数的和

 power = 1
 count = 0
 sum = 0
 while count < 99:
     count += 1
     power += 1
     sum = sum + count*((-1)**power)
 print(sum)

或：

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

6、用户登陆（三次机会重试）

 user_name = 'admin'
 password = 'admin'
 count = 0
 while count < 3:
     count += 1
     name = input ('请输入用户名：')
     if name == user_name:
         pw = input('请输入密码：')
         if pw == password:
             print('登陆成功')
             break
         else :print('密码错误!')
         if count == 3:print('登陆超过三次！请明天重试。')
     else :
         print('用户名不存在!')
         if count == 3 :print('登陆超过三次！请明天重试。')

或：

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