1. 使用while循环输出1 2 3 4 5 6     8 10
count = 0
while count < 10:
    count += 1
    if count == 7 or count == 9:
        continue
    print(count)
2.求1-100的所有数的和

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

3. 输出 1-100 内的所有奇数
count = 0
while count <100:
    count+=1
    if count%2==1:
        print(count)

4. 输出 1-100 内的所有偶数
count = 0
while count <100:
    count+=1
    if count%2==0:
        print(count)

5. 求1-2+3-4+5 ... 99的所有数的和
num = 0
count = 1
while count <= 100:
    if count%2==0:
        num = num-count #num-=count
    elif count%2==1:
        num = num+ count #num+=count
    count += 1
print(num)

6.用户登陆（三次机会重试）
name = "sean"
pwd ="11"
count = 0
while count <3:
     inp_name = input('your name:')
     inp_pwd =input('your pwd:')
     if inp_name == name and inp_pwd == pwd:
         print('success')
         break
     else:
         print('try again')
         count +=1
else:
    print('账号已锁定，请30分钟后再次尝试')

7：猜年龄游戏：允许用户最多尝试3次，3次都没猜对的话，就直接退出，如果猜对了，打印恭喜信息并退出
age_of_sean='18'
count=0
while count < 3:
    age = input('age_of_sean is:')
    if age == age_of_sean:
        print("It's good")
        break
    else:
        print('Try again')
        count+=1
else:
    print('本轮游戏结束，下次加油！')

8：猜年龄游戏升级版
要求：
允许用户最多尝试3次
每尝试3次后，如果还没猜对，就问用户是否还想继续玩，如果回答Y或y, 就继续让其猜3次，以此往复，如果回答N或n，就退出程序
如何猜对了，就直接退出
age_of_sean='18'
count=0
while True:
    if count == 3:
        choice=input('如果继续，请输入Y或y,否则输入N或n退出: ')
        if choice == 'Y' or choice == 'y': #区分大小写
            count=0
        else:
            print('游戏结束，下次继续加油哦')
            break
    age=input('age_of_sean is: ')
    if age == age_of_sean:
        print("It's good")
        break
    count+=1