Generate a random username for Django

django_random_username.py

"""Make a random username for Django, such as 'adf1-2dfa-dfc4-fa9a'."""
import random
import string
from django.contrib.auth import get_user_model


AuthUser = get_user_model()


def make_random_username(length=16,
                         allowed_chars=string.ascii_lowercase + string.digits,
                         slice_length=4, delimiter='-'):
    while True:
        random_string = get_random_string(length,
                                          allowed_chars,
                                          slice_length, delimiter)
        try:
            AuthUser.objects.get(username=random_string)
        except AuthUser.DoesNotExist:
            return random_string


def get_random_string(length=16,
                      allowed_chars=string.ascii_lowercase + string.digits,
                      slice_length=4, delimiter='-'):
    random_string = ''.join([random.choice(allowed_chars)
                             for i in range(length)])
    sliced_random_string_list = [random_string[i:i + slice_length]
                                 for i in range(0, length, slice_length)]
    sliced_random_string = delimiter.join(sliced_random_string_list)
    return sliced_random_string

Supplement about function names.

1. make_random_username
   This function's name is changed to make_random_username according to make_random_password
   Django Manual make_random_password http://bit.ly/2lrb0I9

2. get_random_string
   According to crypto.py, this script also defines get_random_string.
   get_random_string function is defined in crpto.py below for making random password.
   GitHub django/django/utils/crypto.py http://bit.ly/2lxvdLR

AuthUser = get_user_model()

Instead of referring to User directly, you should reference
the user model using django.contrib.auth.get_user_model().
This method will return the currently active user model
– the custom user model if one is specified, or User otherwise.
get_user_model http://bit.ly/2zTZ71M