/ registration __init __（）的TypeError有一个意外的关键字参数'null'

请求方法：GET请求URL：http://127.0.0.1:8000/registration Django版本：1.3.1异常类型：TypeError异常值：

__init__() 得到了一个意外的关键字参数 'null'

异常位置：/usr/local/lib/python2.7/dist-packages/django/forms/fields.py in init，第196行Python可执行文件：/ usr / bin / python Python版本：2.7.2 Python路径：[ '/ home / forent / myprograms / mysite7'，'/ usr / local / lib / python2.7 / dad-package /oauth2-1.5.211-py2.7.egg'，'/ usr / local / lib / python2 . 7 / dist-packages'，'/ usr / local / lib / python2.7 / did-package / python_twitter-0.8.2-py2.7.egg'，'/ usr / local / lib / python2.7 / rem- packages / ipython-0.12-py2.7.egg'，'/ usr / lib / python2.7'，'/ usr / lib / python2.7 / plat-linux2'，'/ usr / lib / python2.7 / lib -tk'，'/ usr / lib / python2.7 / lib-old'，'/ usr / lib / python2.7 / lib-dynload'，'/ usr / local / lib / python2.7 / record-package' ，'/ usr / lib / python2.7 / did-package'，'/ usr / lib / python2.7 / did-package / PIL'，'/ usr / lib / python2.7 / did-package / gst-0.10 '，'/ usr / lib / python2.7 / did-package / gtk-2.0'，'/ usr / lib / pymodules / python2.7'，'/ usr / lib / python2.7 / did-package /ubuntu- sso-client'，'/ usr / lib / python2.7 /dist-packages /ubuntuone-client'，'/ usr / lib / python2.7 / dad-packages /ubuntuone-control l-panel'，'/ usr / lib / python2.7 /dist-packages /ubuntuone-couch'，'/ usr / lib / python2.7 / record-package /ubuntuone-installer'''/ usr / lib / python2 .7 / dist-packages / ubuntuone-storage-protocol']服务器时间：2012年1月27日星期五11:11:22 -0600

＃

view

from django.shortcuts import render_to_response
from registration.models import UserDetails
from forms import UserForm
from django.template import RequestContext
from django.http import HttpResponseRedirect


def user_details(request):
    if request.method=="POST":
        uform=UserForm(request.POST)
        if uform.is_valid():
            profile=uform.save(commit=False)
            profile.save()
        else:
            uform=UserForm()
        return render_to_response('career.html',{'uform':uform},context_instance=RequestContext(request))

#model

from django.db import models

class UserDetails(models.Model):
    fname=models.CharField(max_length=20)
    lname=models.CharField(max_length=20)
    email = models.EmailField()
    address = models.CharField(max_length=50)
    country = models.CharField(max_length=20)
    def __unicode__(self):
        return self.fname
        return self.lname
        return self.email
        return self.address
        return self.country
#forms

from django import forms
from registration.models import UserDetails


class UserForm(forms.Form ):
    fname=forms.CharField(max_length=20, null=True,blank=True)
    lname=forms.CharField(max_length=20, null=True,blank=True)
    email = forms.EmailField(blank=True, null=True)
    address = forms.CharField(max_length=50, null=True,blank=True)
    country = forms.CharField(max_length=20, null=True,blank=True)

#urls

from django.conf.urls.defaults import patterns, include, url

from django.contrib import admin
admin.autodiscover()
# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()

urlpatterns = patterns('',
    # Examples:
     url(r'^registration/$', 'registration.views.user_details', name='user_details'),
    # url(r'^mysite7/', include('mysite7.foo.urls')),

    # Uncomment the admin/doc line below to enable admin documentation:
    # url(r'^admin/doc/', include('django.contrib.admindocs.urls')),

    # Uncomment the next line to enable the admin:
      url(r'^admin/', include(admin.site.urls)),
)

#template 

<form enctype="multipart/form-data" method="post">{% csrf_token %}
    {{ uform.as_p }}
   <input type="submit" ....>
</form>

这是我写的代码..