[Answer]-Django – TypeError while getting args in form

The get_form_class() method, should return the class not object/instance of the form class. So your method can be updated to

def get_form_class(self):
    return ProposalSetForm

However, I’m not sure how will this pass parameters that you need to __init__() of the class.

May be you can define get_form() rather than get_form_class() and return appropriate form instance.