Python 如何在django中对注册表单进行服务器端验证？

我是django的新手，我已经创建了一个注册表单及其工作方式，但是当我尝试验证密码字段以查看password1和password2是否匹配时，我得到了错误。例如，如果我的password1=12345678和password1=TY123456，那么我会得到一个错误“viewwebsite.views.signUp没有返回HttpResponse对象，而是返回None”。基本上，我只想删除错误，而不是重定向到错误页面。有人能帮我吗？如何做注册表单的服务器端验证。非常感谢

view.py

def signUp(request):

    form = UserCreationForm()
    if request.method == 'POST':
        filled_form = UserCreationForm(request.POST)
        if filled_form.is_valid():
            password1 = filled_form.cleaned_data['password1']
            password2 = filled_form.cleaned_data['password2']
            if password1 != password2:
                note='You password does not match'
                return render(request,'signup.html',{'form':form, 'note':note})
            else:
                filled_form.save() 
                return redirect('login')              
    else:
        return render(request,'signup.html',{'form':form})

signup.html

<h1>Sign Up</h1>

<span style="color: red;">{{note}}</span>
<form method="POST">

    {% csrf_token %}

    {{form.as_p}}

  <button type="submit">Sign Up</button>
</form>

from django.contrib import admin
from django.urls import path, include
from website.views import home,signUp

urlpatterns = [
    path('admin/', admin.site.urls),
    path('accounts/',include('django.contrib.auth.urls')),
    path('signup/',signUp, name='signup'),
    path('',home,name='home')
]