Day 13 入门简单练习

1、使用while循环输出1 2 3 4 5 6   8 9 10

count=0while count<10:    count+=1    if count==7:        continue    print(count,end=' ')

2、求1-100的所有数的和

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

3、输出 1-100 内的所有奇数

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

4、输出 1-100 内的所有偶数

count=0while count<100:    count+= 2    print(count)

5、求1-2+3-4+5 ... 99的所有数的和

count=0sum=0while count <99:    count += 1    if count%2>0:        sum+=count    else:        sum-=countprint(sum)

6、用户登陆（三次机会重试）

n=3while n>0:    user = input('Please enter your username:')    password = input('Please enter your password:')    if user=="123" and password=="456":        print('Login Successful')        break    else :        n-=1        print('用户名或密码错误，还可重试%s次。' %n)