• 寫循環猜年齡程序，猜錯三次則打印提示信息並退出循環，猜對也打印提示信息並退出循環

count=0
while count < 3:
    num = input("猜年齡遊戲：")
    guess = int(num)
    if guess == 18:
        print("恭喜你猜對了")
    elif guess > 18:
        print("大了")
    elif guess < 18:
        print("小了")
    count += 1
else:
    print("猜了三次都沒猜對‘
 
")

• 寫while循環嵌套的小例子，用一個tag控制所有while循環的退出

count=0
tag="True"
while True:
    if count >= 3:
        tag="False"
        break
    username = input("請輸入用戶名：")
    password = input("請輸入密碼：")
    if username == "hello" and password == "123":
        print("登錄成功")
        while True:
            
 
if count >= 3:
                print("猜了三次也沒猜中！")
                break
            print("猜數字：")
            guess=int(input("請輸入一個數字："))
            if guess == 18:
                print("猜對了")
            elif guess > 18:
                print("大了")
            else:
                print(
 
"小了")
            count += 1
    else:
        print("用戶名不存在或密碼錯誤！")
        count +=1

Python入門之練習題