diff --git a/django_tools/models.py b/django_tools/models.py
index 0fe72b9..b698344 100644
--- a/django_tools/models.py
+++ b/django_tools/models.py
@@ -1,31 +1,21 @@
-# coding: utf-8
-
 """
     models stuff
     ~~~~~~~~~~~~
 
-    :copyleft: 2011-2017 by the django-tools team, see AUTHORS for more details.
+    :copyleft: 2011-2019 by the django-tools team, see AUTHORS for more details.
     :license: GNU GPL v3 or above, see LICENSE for more details.
 """
 
-from __future__ import absolute_import, division, print_function
 
 from django.conf import settings
 from django.contrib.auth import get_user_model
 from django.db import models
-from django.utils.encoding import python_2_unicode_compatible
+from django.utils.timezone import now
 
 # https://github.com/jedie/django-tools
 from django_tools.middlewares import ThreadLocal
 
-try:
-    from django.utils.timezone import now
-except ImportError:
-    from datetime import datetime
-    now = datetime.now
-
 
-@python_2_unicode_compatible
 class UpdateTimeBaseModel(models.Model):
     """
     Base model to automatically set:
@@ -36,10 +26,11 @@ class UpdateTimeBaseModel(models.Model):
     see also:
     https://github.com/jezdez/django-dbtemplates/commit/2f27327bebe7f2e7b33e5cfb0db517f53a1b9701#commitcomment-1396126
     """
+
     createtime = models.DateTimeField(default=now, editable=False, help_text="Create time")
     lastupdatetime = models.DateTimeField(default=now, editable=False, help_text="Time of the last change.")
 
-    def __str__(self): # to be overwritten
+    def __str__(self):  # to be overwritten
         return "model instance ID:%s" % self.pk
 
     def save(self, *args, **kwargs):
@@ -50,7 +41,6 @@ class Meta:
         abstract = True
 
 
-@python_2_unicode_compatible
 class UpdateUserBaseModel(models.Model):
     """
     Base model to automatically set:
@@ -59,18 +49,27 @@ class UpdateUserBaseModel(models.Model):
 
     Important: "threadlocals middleware" must be used!
     """
-    createby = models.ForeignKey(settings.AUTH_USER_MODEL, editable=False, related_name="%(class)s_createby",
-        null=True, blank=True, # <- If the model used outside a real request (e.g. unittest, db shell)
+
+    createby = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        editable=False,
+        related_name="%(class)s_createby",
+        null=True,
+        blank=True,  # <- If the model used outside a real request (e.g. unittest, db shell)
         help_text="User how create this entry.",
-        on_delete=models.SET_NULL
+        on_delete=models.SET_NULL,
     )
-    lastupdateby = models.ForeignKey(settings.AUTH_USER_MODEL, editable=False, related_name="%(class)s_lastupdateby",
-        null=True, blank=True, # <- If the model used outside a real request (e.g. unittest, db shell)
+    lastupdateby = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        editable=False,
+        related_name="%(class)s_lastupdateby",
+        null=True,
+        blank=True,  # <- If the model used outside a real request (e.g. unittest, db shell)
         help_text="User as last edit this entry.",
-        on_delete=models.SET_NULL
+        on_delete=models.SET_NULL,
     )
 
-    def __str__(self): # to be overwritten
+    def __str__(self):  # to be overwritten
         return "model instance ID:%s" % self.pk
 
     def save(self, *args, **kwargs):
@@ -79,7 +78,7 @@ def save(self, *args, **kwargs):
         if current_user:
             User = get_user_model()
             if isinstance(current_user, User):
-                if self.pk is None or kwargs.get("force_insert", False): # New model entry
+                if self.pk is None or kwargs.get("force_insert", False):  # New model entry
                     self.createby = current_user
                 self.lastupdateby = current_user
 
@@ -100,5 +99,6 @@ class UpdateInfoBaseModel(UpdateTimeBaseModel, UpdateUserBaseModel):
 
     Important: "threadlocals middleware" must be used!
     """
+
     class Meta:
         abstract = True