TypeError: __init__() got an unexpected keyword argument in Django Form & Formset

Question

In following the Django docs on "Passing custom parameters to formset forms", I get the following returned:

__init__() got an unexpected keyword argument 'choices'


File "/Users/emilepetrone/Envs/kishikoi/lib/python3.6/site-packages/django/utils/functional.py" in __get__
  35.         res = instance.__dict__[self.name] = self.func(instance)

File "/Users/emilepetrone/Envs/kishikoi/lib/python3.6/site-packages/django/forms/formsets.py" in forms
  144.                  for i in range(self.total_form_count())]

File "/Users/emilepetrone/Envs/kishikoi/lib/python3.6/site-packages/django/forms/formsets.py" in <listcomp>
  144.                  for i in range(self.total_form_count())]

File "/Users/emilepetrone/Envs/kishikoi/lib/python3.6/site-packages/django/forms/formsets.py" in _construct_form
  182.         form = self.form(**defaults)

File "/Users/emilepetrone/Sites/kishikoi/kishikoi/transactions/forms.py" in __init__
  119.         super(SoldTransactionForm, self).__init__(*args, **kwargs)

Exception Type: TypeError at /transactions/create/sell/transactions/31tmhqsplg41jc8c/
Exception Value: __init__() got an unexpected keyword argument 'choices'

Here is my view where I follow the documentation and pass 'choices' in the formset form_kwargs.

class SellTransactionsView(LoginRequiredMixin, SetHeadlineMixin, UpdateView):
    model = Transaction
    template_name = "transactions/soldtransaction_form.html"
    headline = "Sell Transaction"
    fields = ['num_shares']

    def get_object(self):
        return Transaction.objects.get(
            user=self.request.user,
            identifier=self.kwargs['identifier']
        )

    def get_choices(self):
        transaction = self.get_object()
        choices = Transaction.objects.filter(
            user=transaction.user,
        ).exclude(identifier=transaction.identifier)
        return choices

    def get_context_data(self, *args, **kwargs):
        context = super(SellTransactionsView, self).get_context_data(
            *args, **kwargs)
        choices = self.get_choices()
        formset = SoldFormset(form_kwargs={'choices': choices})
        context.update({
            "formset": formset,
        })
        return context

My Form & Formset- I'm using a forms.Form because I will be using these fields to update a different field in form.is_valid().

class SoldTransactionForm(forms.Form):

    old_transaction = forms.ChoiceField()

    num_shares = forms.IntegerField(
        min_value=0
    )

    class Meta:
        fields = [
            'old_transaction',
            'num_shares',
        ]

    def __init__(self, *args, **kwargs):
        super(SoldTransactionForm, self).__init__(*args, **kwargs)
        self.fields['old_transaction'].queryset = kwargs.pop('choices')

SoldFormset = forms.formset_factory(
    SoldTransactionForm,
    formset=forms.BaseFormSet,
    extra=2
)

SOLUTION

For others that hit this, the kwargs.pop('choices') did need to be above the Super() in the form.init

This resolved the error, but then presented a formset without loading the data in the ChoiceField. I changed the field to a ModelChoiceField & set queryset=None (to be changed in the init. That resolved the issues.

Answer 1

Pop before you call super:

def __init__(self, *args, **kwargs):

        queryset = kwargs.pop('choices')

        super(SoldTransactionForm, self).__init__(*args, **kwargs)

        self.fields['old_transaction'].queryset = queryset