admin.py

from django import forms
from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as ContribUserAdmin
from django.contrib.auth.forms import ReadOnlyPasswordHashField

from .models import User


class UserCreationForm(forms.ModelForm):
    password1 = forms.CharField(label='Password', widget=forms.PasswordInput)
    password2 = forms.CharField(label='Password confirmation', widget=forms.PasswordInput)

    class Meta:
        model = User
        fields = ('email',)

    def clean_password2(self):
        password1 = self.cleaned_data.get('password1')
        password2 = self.cleaned_data.get('password2')
        if password1 and password2 and password1 != password2:
            raise forms.ValidationError("Passwords don't match")
        return password2

    def save(self, commit=True):
        user = super(UserCreationForm, self).save(commit=False)
        user.set_password(self.cleaned_data['password1'])
        if commit:
            user.save()
        return user


class UserChangeForm(forms.ModelForm):
    password = ReadOnlyPasswordHashField()

    class Meta:
        model = User

    def clean_password(self):
        return self.initial['password']


class UserAdmin(ContribUserAdmin):
    form = UserChangeForm
    add_form = UserCreationForm

    list_display = ('email', 'is_staff')
    list_filter = ('is_staff',)
    fieldsets = (
        (None, {'fields': ('email', 'password')}),
        ('Permissions', {'fields': ('is_staff',)}),
        ('Important dates', {'fields': ('last_login',)})
    )
    add_fieldsets = (
        (None, {'classes': ('wide',), 'fields': ('email', 'password1', 'password2')}),
    )
    search_fields = ('email',)
    ordering = ('email',)
    filter_horizontal = ()

admin.site.register(User, UserAdmin)

models.py

from django.contrib.auth.models import AbstractBaseUser, BaseUserManager, PermissionsMixin
from django.db import models
from django.utils import timezone
from django.utils.translation import ugettext_lazy as _

__all__ = ('User',)


class UserManager(BaseUserManager):
    def create_user(self, email, password=None, **extra_fields):
        if not email:
            raise ValueError('The given email must be set')
        email = UserManager.normalize_email(email)

        now = timezone.now()

        user = self.model(email=email, is_staff=False, is_active=True,
                          is_superuser=False, last_login=now, date_joined=now,
                          **extra_fields)

        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_superuser(self, email, password, **extra_fields):
        user = self.create_user(email, password, **extra_fields)
        user.is_staff = True
        user.is_active = True
        user.is_superuser = True
        user.save(using=self._db)
        return user


class User(AbstractBaseUser, PermissionsMixin):
    email = models.EmailField(unique=True, db_index=True)

    first_name = models.CharField(_('first name'), max_length=30, blank=True)
    last_name = models.CharField(_('last name'), max_length=30, blank=True)
    is_staff = models.BooleanField(_('staff status'), default=False,
        help_text=_('Designates whether the user can log into this admin '
                    'site.'))
    is_active = models.BooleanField(_('active'), default=True,
        help_text=_('Designates whether this user should be treated as '
                    'active. Unselect this instead of deleting accounts.'))
    date_joined = models.DateTimeField(_('date joined'), default=timezone.now)

    objects = UserManager()

    USERNAME_FIELD = 'email'

    def get_full_name(self):
        return '{} {}'.format(self.first_name, self.last_name)

    def get_short_name(self):
        return '{}'.format(self.first_name)

settings.py

AUTH_USER_MODEL = 'app.User'