Must complete at least one form in formset_factory()

from django import forms

class PersonForm(forms.Form):
  first_name = forms.CharField(max_length=255)
  last_name = forms.CharField(max_length=255)
  email = forms.EmailField(max_length=255)
  
class NoEmptyFormsAllowedBaseFormSet(forms.formsets.BaseFormSet):
  """
  Won't allow formset_factory to be submitted with no forms
  """
  def clean(self):
    if "cleaned_data" in self.forms[0] and not self.forms[0].cleaned_data:
      raise forms.ValidationError, "Please fill in at least one form"



formset = formset_factory(PersonForm, extra=1, formset=NoEmptyFormsAllowedBaseFormSet)