email_address_usernames.py

gistfile1.py

# admin.py - get the User form working the Django Admin w/ email usernames.

from django.contrib.auth.forms import UserChangeForm
from django.contrib.auth.admin import UserAdmin

class EmailUserChangeForm(UserChangeForm):
    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^[\w@.]+$',
        help_text = _("Required. 30 characters or fewer. Valid email addresses only."))

class EmailUserAdmin(UAdmin):
    form = EmailUserChangeForm

# ... register the admin ...

# views.py - email addresses can be long so relax the login form max_length.
from django.contrib.auth.forms import AuthenticationForm

AuthenticationForm.base_fields["username"].max_length = 60
AuthenticationForm.base_fields["username"].widget.attrs["maxlength"] = 60