' <' not supported between instances of 'NoneType' and 'int' django views.py

Question

            {% if guess == rand_num %}
            <h1>{{message1}}</h1>
            {% elif guess > rand_num %}
            <h1>{{message3_a}}</h1>
            <h1>{{message3_b}}</h1>
            {% elif guess < rand_num %}
            <h1>{{message2_a}}</h1>
            <h1>{{message2_b}}</h1>
            {% endif %}

wive.py

def easy(request, ):
    rand_num = random.choice(lst)
    print(rand_num)
    attempts = 11
    for _ in range(0, 10):
        # print(f"You have {attempts} remaining  to guess the number.")
        # guess = int(input("Make a guess: "))
        guess = request.GET.get('guessed_number')
        if guess == rand_num:
            return render(request, 'easy.html', {'attempts': attempts, "message1": f"You got it! The anshwer was {rand_num}"})  
            break
        elif guess < rand_num:
            attempts -= 1
            return render(request, 'easy.html', {'attempts': attempts, "message2_a": "Too Low", "message2_b": "Guess again"})  
        elif guess > rand_num:
            attempts -= 1
            return render(request, 'easy.html', {'attempts': attempts, "message3_a": "Too High", "message2_b": "Guess again"})  
        attempts -= 1
        return render(request, 'easy.html', {'attempts': attempts, 'guess': guess, 'rand_num': rand_num})
    return render(request, 'easy.html')

我正在尝试运行此Django代码，但它不起作用。

您可以在执行比较之前明确检查变量是否存在。

{% if guess is not None and rand_num is not None %}
    {% if guess == rand_num %}
        <h1>{{ message1 }}</h1>
    {% elif guess > rand_num %}
        <h1>{{ message3_a }}</h1>
        <h1>{{ message3_b }}</h1>
    {% elif guess < rand_num %}
        <h1>{{ message2_a }}</h1>
        <h1>{{ message2_b }}</h1>
    {% endif %}
{% else %}
    <h1>No guess or random number provided.</h1>
{% endif %}

在线，您可以使用默认过滤器在不存在或不存在的情况下提供默认值

Answer 1

您可能想做更多的事情来验证您的

guessed_number

参数的存在并最终成为int。那么此逻辑的其余部分应该更具气密性。 您可以：

确保查询参数首先存在，并且不是非

Answer 2

确保猜测是一个实际的整数

 guess = request.GET.get('guessed_number', None)
 if not guess:
     return HttpResponseBadRequest('You must provide a guess number')

 try:
     guess_number = int(guess)

 except ValueError:
     return HttpResponseBadRequest('Guess number must be an integer')

 # do the rest of the logic with assurance that "guess" is an int you can use