python基础作业练习-20171214

1、使用while循环输入 1 2 3 4 5 6     8 9 10

count = 1 

while count <= 10:
    if count == 7:
        count = count + 1
        continue
    print(count)
    count = count + 1

　　

2、求1-100的所有数的和

count = 1 
sum = 0

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

print(sum)

3、输出 1-100 内的所有奇数

count = 1 

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

4、输出 1-100 内的所有偶数

count = 1

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

5、求1-2+3-4+5 ... 99的所有数的和

count = 1 
sum = 0 

while count <= 99:
	if count ==1:
		sum = count
		count = count + 1
		continue
	else:
		if count % 2 ==1:
			sum = sum + count
			count = count + 1
		else:
			sum = sum - count
			count = count + 1
print(sum)

6、用户登陆（三次机会重试）

count = 1
sum = 0

while count <= 3:
	username = input('请输入用户名：')
	password = input('请输入用户密码：')
	if username == 'Jason' and password == '123':
		print('登录成功，欢迎“Jason”回来！')
		break
	else:
		sum = 3 - count
		print('用户名或密码错误，请重新输入，目前还剩余'+str(sum)+'机会！')
		count = count + 1