Django override default Django form

Question

My purpose is to override default Django PasswordResetForm 's clean_email() method. The purpose of that is that I want to check if user exists by username, not by email (its just how my apps business logic works). Then I will be able to reset his password. How should I override the method ? And more iportantly - if I would do it, the whole password reset system wont break ?

This is the default Django code:

class PasswordResetForm(forms.Form):
error_messages = {
    'unknown': _("That email address doesn't have an associated "
                 "user account. Are you sure you've registered?"),
    'unusable': _("The user account associated with this email "
                  "address cannot reset the password."),
}
email = forms.EmailField(label=_("Email"), max_length=254)

def clean_email(self):
    """
    Validates that an active user exists with the given email address.
    """
    UserModel = get_user_model()
    email = self.cleaned_data["email"]
    self.users_cache = UserModel._default_manager.filter(email__iexact=email)
    if not len(self.users_cache):
        raise forms.ValidationError(self.error_messages['unknown'])
    if not any(user.is_active for user in self.users_cache):
        # none of the filtered users are active
        raise forms.ValidationError(self.error_messages['unknown'])
    if any((user.password == UNUSABLE_PASSWORD)
           for user in self.users_cache):
        raise forms.ValidationError(self.error_messages['unusable'])
    return email

def save(self, domain_override=None,
         subject_template_name='registration/password_reset_subject.txt',
         email_template_name='registration/password_reset_email.html',
         use_https=False, token_generator=default_token_generator,
         from_email=None, request=None):
    """
    Generates a one-use only link for resetting password and sends to the
    user.
    """
    from django.core.mail import send_mail
    for user in self.users_cache:
        if not domain_override:
            current_site = get_current_site(request)
            site_name = current_site.name
            domain = current_site.domain
        else:
            site_name = domain = domain_override
        c = {
            'email': user.email,
            'domain': domain,
            'site_name': site_name,
            'uid': int_to_base36(user.pk),
            'user': user,
            'token': token_generator.make_token(user),
            'protocol': use_https and 'https' or 'http',
        }
        subject = loader.render_to_string(subject_template_name, c)
        # Email subject *must not* contain newlines
        subject = ''.join(subject.splitlines())
        email = loader.render_to_string(email_template_name, c)
        send_mail(subject, email, from_email, [user.email])

Answer 1

I think you can write a clean_username method to achieve what you want. This might help: Checking if username exists in Django

Answer 2

The reason why I wanted to achieve that was that I wanted to use email as a username in Django Registration. I thought about just naming Django username field as email field, but I was not aware that since Django 1.5 you can specify your own custom User model .