Estoy usando Django allauth como marco de mi cuenta de usuario para mi sitio django. Los documentos muestran que hay una ACCOUNT_USERNAME_MIN_LENGTH sin embargo no hayACCOUNT_USERNAME_MAX_LENGTH por alguna razón

¿Hay alguna forma de crear una longitud máxima para el nombre de usuario?

Aquí está mi formulario de registro personalizado de Allah, ¿tal vez pueda hacer algo aquí:

class AllauthSignupForm(forms.Form):

    captcha = ReCaptchaField(
        public_key=config("RECAPTCHA_PUBLIC_KEY"),
        private_key=config("RECAPTCHA_PRIVATE_KEY"),
    )

    class Meta:
        model = User

    def signup(self, request, user):
        """ Required, or else it throws deprecation warnings """
        pass

Editar Intentando subclasificar SignupView

draft1 / forms.py

class AllauthSignupForm(SignupForm):
    def __init__(self, *args, **kwargs):
        super(AllauthSignupForm, self).__init__(*args, **kwargs)
        self.fields['username']['validators'] += MaxLengthValidator(150,
                                                                    "Username should be less than 150 character long")

    captcha = ReCaptchaField(
        public_key=config("RECAPTCHA_PUBLIC_KEY"),
        private_key=config("RECAPTCHA_PRIVATE_KEY"),
    )

    class Meta:
        model = User

    def signup(self, request, user):
        """ Required, or else it throws deprecation warnings """
        pass

draft1 / views.py

from allauth.account.views import SignupView

class MySignupView(SignupView):
    form_class = AllauthSignupForm

allauth / account / urls.py

url(r"^signup/$", MySignupView.as_view(), name="account_signup"),

draft1 / settings.py

ACCOUNT_SIGNUP_FORM_CLASS = 'draft1.forms.AllauthSignupForm'

El código anterior devuelve este error:

Traceback (most recent call last):
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/utils/autoreload.py", line 228, in wrapper
    fn(*args, **kwargs)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 125, in inner_run
    self.check(display_num_errors=True)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/core/management/base.py", line 359, in check
    include_deployment_checks=include_deployment_checks,
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/core/management/base.py", line 346, in _run_checks
    return checks.run_checks(**kwargs)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/core/checks/registry.py", line 81, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/core/checks/urls.py", line 16, in check_url_config
    return check_resolver(resolver)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/core/checks/urls.py", line 26, in check_resolver
    return check_method()
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/urls/resolvers.py", line 254, in check
    for pattern in self.url_patterns:
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/urls/resolvers.py", line 405, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/django/urls/resolvers.py", line 398, in urlconf_module
    return import_module(self.urlconf_name)
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/Users/zorgan/Desktop/vorsso/venvor/draft1/urls.py", line 6, in <module>
    from . import views
  File "/Users/zorgan/Desktop/vorsso/venvor/draft1/views.py", line 11, in <module>
    from .forms import UserSettingsForm
  File "/Users/zorgan/Desktop/vorsso/venvor/draft1/forms.py", line 8, in <module>
    from allauth.account.forms import SignupForm
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/allauth/account/forms.py", line 228, in <module>
    class BaseSignupForm(_base_signup_form_class()):
  File "/Users/zorgan/Desktop/postr1/lib/python3.5/site-packages/allauth/account/forms.py", line 216, in _base_signup_form_class
    fc_classname))
django.core.exceptions.ImproperlyConfigured: Module "draft1.forms" does not define a "AllauthSignupForm" class