python猜我的号码练习在edX上标记错误

Question

该程序的工作原理如下：您（用户）认为0（包括）和100（不包括）之间的整数。计算机猜测，你给它输入 - 它的猜测是太高还是太低？使用二分搜索，计算机将猜测用户的密码！

我的代码：

使用二分法猜测数字

要求输入来自用户的号码

high = 100
low = 0
correct = False
response = ""
user_number = input("Please think of a number between 0 and 100!")
while (response != "c"):
    guess = int((high + low)/2)
    print("Is your secret number", guess, "?")
    response = input("Enter 'h' to indicate the guess is too high. Enter 'l' to indicate the guess is too low. Enter 'c' to indicate I guessed correctly")
    if not  (response == "h" or response == "c" or response == "l"):
        print("Sorry, I did not understand your input.")
    elif (response is "h"):
        high = guess
    elif (response is "l"):
        low = guess

print ("Game over. Your secret number was:", guess)

目前EdX网站将我的答案标记为不正确，我通过尝试输入数字（如83,8,42）检查了输出，它正确显示为edX网站代码显示。有人可以给我一些关于我的代码有缺陷的建议吗？谢谢。