Question

我试图在我创建的ModelForm上调用is_valid（），并且出于某种原因它给出了异常：

TypeError at /submit/
%d format: a number is required, not NoneType

有问题的观点是：

def submitted_file(request):
    if request.method == 'POST':
        test = PickUserForm(request.POST)
        if test.is_valid():
            print "test"
            test.save()
    return HttpResponse("File uploaded.")

与此ModelForm连接：

class PickUserForm(ModelForm):

    class Meta:
        model = Submission
        widgets = {
            'comment' : Textarea(attrs={'cols':80, 'rows':20}),
        }
        fields = ['p1_name', 'p2_name', 'p1_url', 'p2_url', 'p1_uid', 'p2_uid', 'p1_subregion', 'p2_subregion', 'comment', 'hacker', 'file']

提交模型非常简单：

class Submission(models.Model):
    p1_name = models.CharField()
    p2_name = models.CharField()
    p1_url = models.CharField()
    p2_url = models.CharField()
    p1_uid = models.IntegerField()
    p2_uid = models.IntegerField()
    p1_subregion = models.IntegerField()
    p2_subregion = models.IntegerField()
    comment = models.CharField()
    hacker = models.CharField()
    file = models.CharField()

堆栈跟踪非常有用，并指向functional.py in __mod__, line 160。我已经检查了这行代码，但无法理解它。堆栈跟踪的其他部分是：

Traceback:
115. response = callback(request, *callback_args, **callback_kwargs)
44. if test.is_valid():

我已经探索了堆栈跟踪附带的POST数据，并没有看到任何异常，所以我不明白这个NoneType来自哪里。有一点需要注意的是＆＃34;文件已上传＆＃34;因为我从另一个表单继承了文件上传数据，所以有点误导，这就是为什么我只传入request.POST而不是request.FILES。

编辑：完整的堆栈跟踪：

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/submit/

Django Version: 1.5.1
Python Version: 2.7.3
Installed Applications:
('django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.admin')
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware')


Traceback:
File "/<project_dir>/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  115.                         response = callback(request, *callback_args,     **callback_kwargs)
File "/<project_dir>/views.py" in submitted_file
  44.       if test.is_valid():
File "/<project_dir>/local/lib/python2.7/site-packages/django/forms/forms.py" in     is_valid
  126.         return self.is_bound and not bool(self.errors)
File "/<project_dir>/local/lib/python2.7/site-packages/django/forms/forms.py" in     _get_errors
  117.             self.full_clean()
File "/<project_dir>/local/lib/python2.7/site-packages/django/forms/forms.py" in     full_clean
  274.         self._post_clean()
File "/<project_dir>/local/lib/python2.7/site-packages/django/forms/models.py" in     _post_clean
  332.             self.instance.clean_fields(exclude=exclude)
File "/<project_dir>/local/lib/python2.7/site-packages/django/db/models/base.py" in     clean_fields
  946.                 setattr(self, f.attname, f.clean(raw_value, self))
File "/<project_dir>/local/lib/python2.7/site-packages/django/db/models/fields    /__init__.py" in clean
  213.         self.run_validators(value)
File "/<project_dir>/local/lib/python2.7/site-packages/django/db/models/fields    /__init__.py" in run_validators
  165.                 v(value)
File "/<project_dir>/local/lib/python2.7/site-packages/django/core/validators.py" in     __call__
  168.                 self.message % params,
File "/<project_dir>/local/lib/python2.7/site-packages/django/utils/functional.py" in     __mod__
  160.                 return six.text_type(self) % rhs

Exception Type: TypeError at /submit/
Exception Value: %d format: a number is required, not NoneType

edit2：忘了主要的黄色部分：

TypeError at /submit/

%d format: a number is required, not NoneType

Request Method:     POST
Request URL:    http://127.0.0.1:8000/submit/
Django Version:     1.5.1
Exception Type:     TypeError
Exception Value:    

%d format: a number is required, not NoneType

Exception Location:     <project_dir>/local/lib/python2.7/site-    packages/django/utils/functional.py in __mod__, line 160
Python Executable:  <project_dir>/bin/python
Python Version:     2.7.3
Python Path:    

['<project_dir>',
 '<project_dir>/local/lib/python2.7/site-packages/setuptools-    0.6c11-py2.7.egg',
 '<project_dir>/local/lib/python2.7/site-packages/pip-1.3.1-    py2.7.egg',
 '/home/trevor/django_projects/SC2Hackers/lib/python2.7/site-packages/setuptools-0.6c11-    py2.7.egg',
 '<project_dir>/lib/python2.7/site-packages/pip-1.3.1-    py2.7.egg',
 '<project_dir>/lib/python2.7',
 '<project_dir>/lib/python2.7/plat-linux2',
 '<project_dir>/lib/python2.7/lib-tk',
 '<project_dir>/lib/python2.7/lib-old',
 '<project_dir>/lib/python2.7/lib-dynload',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-linux2',
 '/usr/lib/python2.7/lib-tk',
 '<project_dir>/local/lib/python2.7/site-packages',
 '<project_dir>/lib/python2.7/site-packages']

Server time:    Wed, 5 Jun 2013 19:23:31 -0500

Answer 1

根据Django documentation，max_length是CharField的必需参数。

因此，将max_length添加到CharField应该修复它。

在将基于预先存在的Form的新Model和ModelForm添加到Django 1.4项目中的应用程序时，我遇到了同样的问题。我没有在Form中使用max_length（它没有任何问题），而且由于CharField对于Form和Model来说很常见，所以我尝试使用该字段。 KABOOM！

幸运的是，我在文档中注意到了“必需”这个词。错误消息和回溯不是很有帮助。

％d格式：需要一个数字，而不是is_valid（）的NoneType

1 个答案: