set field attributes in inherited classes in a DRY fashion in Django

Question

My code is below. I am actually redefining my vehicle_make just to change its initial value in the inherited class (UpdateForm). I am looking for a DRY approach. I tried field['fieldname'].initial="value", but that gives keyerror.

class BaseInputForm(forms.ModelForm):
    class Meta:
        model = Vehicle
        exclude = ('vehicle_make','vehicle_model')

    def __init__(self, *args, **kwargs):
        super(SearchInputForm, self).__init__(*args, **kwargs)
        self.fields['vehicle_make']=forms.ChoiceField(
                    initial="NA",
                    label="Car make",
                    choices=MAKES, 
                    widget=forms.Select(attrs={'id':'makes'})
                    )



   class CreateForm(BaseInputForm):
          pass



    class UpdateForm(BaseInputForm):
         def __init__(self, *args, **kwargs):
            super(SearchUpdateForm, self).__init__(*args, **kwargs)
            self.vehicle_make=self.instance.vehicle_make
            self.fields['vehicle_make'] = forms.ChoiceField(
                        initial=self.vehicle_make,
                        label="Car make",
                        choices=MAKES,
                        widget=forms.Select(attrs={'id':'makes'})
                        )
          #self.fields['vehicle_make'].initial=self.instance.vehicle_model

Answer 1

Try:

self.fields['fieldname'].initial="value"

self is keyword. you are missing that

Answer 2

Why don't you simply use the get_initial method?