Add fallback default for AUTH_PASSWORD_VALIDATORS.

password_validation/conf.py

@@ -0,0 +1,10 @@
+from django.conf import settings as django_settings
+
+
+class SettingsProxy(object):
+    @property
+    def AUTH_PASSWORD_VALIDATORS(self):
+        return getattr(django_settings, 'AUTH_PASSWORD_VALIDATORS', [])
+
+
+settings = SettingsProxy()

password_validation/test/test_settings.py

@@ -0,0 +1,6 @@
+from password_validation import get_default_password_validators
+
+
+def test_default_setting():
+    """Defaults to no password validation."""
+    assert get_default_password_validators() == []

password_validation/validation.py

@@ -3,6 +3,9 @@
 Copied from django/contrib/auth/password_validation.py at commit
 9851e54121b3eebd3a7a29de3ed874d82554396b
 
+The only modification is changing `from django.conf import settings` to `from
+password_validation.conf import settings`.
+
 """
 from __future__ import unicode_literals
 
@@ -11,7 +14,7 @@
 import re
 from difflib import SequenceMatcher
 
-from django.conf import settings
+from password_validation.conf import settings
 from django.core.exceptions import ImproperlyConfigured, ValidationError
 from django.utils import lru_cache
 from django.utils._os import upath