#kustomowy emailauthbackend

from django.contrib.auth.models import User

class EmailAuthBackend():

    def authenticate(self,request,username,password):
        try:
            user = User.objects.get(email=username)
            success = user.check_password(password)
            if success:
                return user
        except User.DoesNotExist:
             try:
                user = User.objects.get(username=username)
                if user.check_password(password):
                    return user
             except User.DoesNotExist:
                return None

    def get_user(self,uid):
        try:
            return User.objects.get(pk=uid)
        except:
            return None

    def has_perm(self, user_obj, perm, obj=None):
        if user_obj.username == settings.ADMIN_LOGIN:
            return True
        else:
            return False


#login.html
    {% extends 'home/base.html' %}

{% block title %}Login{% endblock %}



{% block content %}

<h1> Log in </h1>
<form method="post" action="{% url 'answer:login_view' %}">
{% csrf_token %}
  <table>
  <tr>
   <td>{{ form.email.label_tag }}</td>
   <td>{{ form.email }}</td>
  </tr>
  <tr>
   <td>{{ form.password.label_tag }}</td>
   <td>{{ form.password }}</td>
  </tr>
  </table>

  <input type="submit" value="login" />
  <input type="hidden" name="next" value="{{ next }}" />
</form>
{% endblock %}


widok


def login_view(request):
    from django.contrib.auth.forms import AuthenticationForm
    form = LoginForm(request.POST or None)
    if request.method == 'POST' and form.is_valid():
        user = authenticate(email=user, password=password)
        login(request, user)
        return redirect('index')
    else:
        return HttpResponseRedirect('Error')