Django: agregue un campo a un modelo

Question

Quiero agregar un campo adicional a un ModelForm. Parece fácil, pero me da el siguiente error:

Django Version: 1.4 pre-alpha SVN-16573 
Exception Type: TypeError 
Exception Value:  
argument of type 'NoneType' is not iterable 
Exception Location: /usr/local/lib/django-trunk/django/forms/models.py in construct_instance, line 39 
Python Executable: /usr/bin/python 
Python Version: 2.6.6 

Este es el código:

class NodeForm(forms.ModelForm): 
    password2 = forms.CharField(max_length=20, required=True, widget=forms.PasswordInput()) 

    class Meta: 
     model = Node 

    def __init__(self, *args, **kwargs): 
     super(NodeForm, self).__init__(*args, **kwargs) 
     # css classes for fields 
     for v in self.fields: 
      self.fields[v].widget.attrs['class'] = 'text ui-widget-content ui-corner-all' 

    def clean(self): 
     ''' Calls parent clean() and performs additional validation for the password field ''' 
     super(NodeForm, self).clean() 
     password = self.cleaned_data.get('password') 
     password2 = self.cleaned_data.get('password2') 
     # password and password2 must be the same 
     if password != password2: 
      raise forms.ValidationError('I due campi password non corrispondono.') 

yo no era capaz de arreglarlo. ¿Qué estoy haciendo mal?

Answer 1

debe devolver los datos limpiada de clean método como se documenta here Eso es:

def clean(self): 
    # perform checks 
    return self.cleaned_data