[Django]-Django Registration Redux: how to change the unique identifier from username to email and use email as login

You can override registration form like this

from registration.forms import RegistrationForm
class MyRegForm(RegistrationForm):
    username = forms.CharField(max_length=254, required=False, widget=forms.HiddenInput())

    def clean_email(self):
        email = self.cleaned_data['email']
        self.cleaned_data['username'] = email
        return email

And then add this to settings file (read this link for details)

REGISTRATION_FORM = 'app.forms.MyRegForm'

This will set the email to username field as well and then everything will work as email is now the username.

The only problem is that username field has a max lenght of 30 in DB. So emails longer than 30 chars will raise DB exception. To solve that override the user model (read this for details).

The easiest way to achieve this is to made your own custom User Model.

This is the example

class MyUser(AbstractBaseUser):
    email = models.EmailField(
        verbose_name='email address',
        max_length=255,
        unique=True,
    )
    date_of_birth = models.DateField()
    is_active = models.BooleanField(default=True)
    is_admin = models.BooleanField(default=False)

    objects = MyUserManager()

    USERNAME_FIELD = 'email' 

Then, you need to set the User Model in your Django settings. https://docs.djangoproject.com/en/1.8/ref/settings/#auth-user-model

You will want to use AbstractBaseUser. Docs are here:

https://docs.djangoproject.com/en/1.8/topics/auth/customizing/

Good luck!