Python错误：视图form.formapp.views.contact未返回HttpResponse对象。解决方法

Question

我刚开始学Python，现在在用视图和网址处理一个表单……我的项目叫做 projec1，而我的应用程序叫 usersapp。

这是我的 **usersapp/views.py** 文件。

from django.http import HttpResponse
from django.shortcuts import render_to_response
from django.template import RequestContext
from users.form import ContactForm

def contact(request):
    if request.method == "POST":
        contact_form = ContactForm(request.POST)
        if contact_form.is_valid():
            success = True
            username = contact_form.cleaned_data['username']
            password = contact_form.cleaned_data['password']
    else:
        contact_form = ContactForm()
        return render_to_response('contact.html', {'contact_form': contact_form})

这是我的 usersapp/contact.html 文件。

{%block title%}
Contact
{%endblock%}
{%block content%}
<h2>Contact</h2>
    <form action ='.' method = 'POST'>
        {{contact_form.as_p}}
        <input type ="Submit" name = "submit" value = "send">  
    </form>
{%endblock%}

这是我的 usersapp/form.py 文件。

from django import forms

class ContactForm(forms.Form):
    username = forms.CharField()
    password = forms.CharField()

这是我的 projec1/urls.py 文件。

 from django.conf.urls import patterns, include, url
 from django.conf.urls.defaults import *
 from users.views import login
 from users.views import contact

 urlpatterns = patterns('',
                   ('^contact/$', contact),
                     )

我遇到了这个错误。

  TypeError at /
  Error when calling the metaclass bases
  module.__init__() takes at most 2 arguments (3 given)
  Request Method:   GET
  Request URL:  http://127.0.0.1:8000/
  Django Version:   1.4.3
  Exception Type:   TypeError
  Exception Value:  
  Error when calling the metaclass bases
  module.__init__() takes at most 2 arguments (3 given)

我的错误是：

  NameError at /contact
  name 'forms' is not defined
  Request Method:   GET
  Request URL:  http://127.0.0.1:8000/contact
  Django Version:   1.4.3
  Exception Type:   NameError
  Exception Value:  
  name 'forms' is not defined
  Exception Location: C:\Users\Documents\MyProjects\projec1\users\form.py    
  in<module>,line 2
  Python Executable:    C:\Python27\python.exe

请有人指导一下我，谢谢你们！

Answer 1

表单类的定义是错误的，这可能导致了那个错误：

from django import forms

# Inherit from `forms.Form`, not from `forms`:
class ContactForm(forms.Form):
    username = forms.CharField()
    password = forms.CharField()

在视图函数中也有几个问题：

def contact(request):
    if request.method == "POST":
        contact_form = ContactForm(request.POST)

        # Not `contact_form is valid()`:
        if contact_form.is_valid():
            success = True

            # `cleaned_data` is all lowercase:
            username = contact_form.cleaned_data['username']
            password = contact_form.cleaned_data['password']
    else:
        contact_form = ContactForm()

    # You always want to return a response. Putting the return statement
    # here will fix the error mentioned in the question's title. The 
    # second argument makes `contact_form` available from the template:
    return render_to_response('contact.html', {
        'contact_form': contact_form
    })