Email-based user

email_based_user.py

from random import choice
from string import ascii_lowercase, digits
from django.db import transaction
from django.db.models import User


USERNAME_CHARS = ascii_lowercase + digits


@transaction.commit_on_success
def create_email_based_user(email):
    username = generate_random_username()
    email = User.objects.normalize_email(email)

    user = User(username=username, email=email, is_active=False)
    user.set_unusable_password()
    user.full_clean()
    user.save()
    return user
    

def generate_random_username(length=30, max_attempts=100):
    for i in xrange(max_attempts):
        username = ''.join(choice(USERNAME_CHARS) for i in xrange(length))
        if not User.objects.filter(username=username).exists():
            return username
    raise ValueError('Maximum attempts made to generate username')