Rest Framework (Custom User + TokenAuthentication)

from django.contrib.auth import authenticate
from django.utils.translation import gettext_lazy as _

from rest_framework import serializers

class EmailAuthTokenSerializer(serializers.Serializer):
    email = serializers.CharField(
        label=_("email"),
        write_only=True
    )
    password = serializers.CharField(
        label=_("Password"),
        style={'input_type': 'password'},
        trim_whitespace=False,
        write_only=True
    )
    token = serializers.CharField(
        label=_("Token"),
        read_only=True
    )

    def validate(self, attrs):
        email = attrs.get('email')
        password = attrs.get('password')

        if email and password:
            user = authenticate(request=self.context.get('request'),
                                email=email, password=password)

            # The authenticate call simply returns None for is_active=False
            # users. (Assuming the default ModelBackend authentication
            # backend.)
            if not user:
                msg = _('Unable to log in with provided credentials.')
                raise serializers.ValidationError(msg, code='authorization')
        else:
            msg = _('Must include "email" and "password".')
            raise serializers.ValidationError(msg, code='authorization')

        attrs['user'] = user
        return attrs

from rest_framework.authtoken.views import ObtainAuthToken

from .serializers import EmailAuthTokenSerializer

class EmailObtainAuthToken(ObtainAuthToken):
    serializer_class = EmailAuthTokenSerializer

obtain_auth_token = EmailObtainAuthToken.as_view()

from django.urls import path

from . import views

urlpatterns = [
    # ...
    path('api-token-auth/', views.obtain_auth_token),
]