How to remove a field from the parent Form in a subclass?

Question

class LoginForm(forms.Form):     nickname = forms.CharField(max_length=100)     username = forms.CharField(max_length=100)     password = forms.CharField(widget=forms.PasswordInput)   class LoginFormWithoutNickname(LoginForm):     # i don't want the field nickname here     nickname = None #?? 

Is there a way to achieve this?

Note: i don't have a ModelForm, so the Meta class with exclude doesn't work.

Answer 1

You can alter the fields in a subclass by overriding the init method:

class LoginFormWithoutNickname(LoginForm):     def __init__(self, *args, **kwargs):         super(LoginFormWithoutNickname, self).__init__(*args, **kwargs)         self.fields.pop('nickname') 

Answer 2

Django 1.7 addressed this in commit b16dd1fe019 for ticket #8620. In Django 1.7, it becomes possible to do nickname = None in the subclass as the OP suggests. From the documentation changes in the commit:

It's possible to opt-out from a Field inherited from a parent class by shadowing it. While any non-Field value works for this purpose, it's recommended to use None to make it explicit that a field is being nullified.