Django 3 compatibility

.travis.yml

@@ -67,6 +67,10 @@ matrix:
       env: TOX_ENV=py36-django22
     - python: 3.7
       env: TOX_ENV=py37-django22
+    - python: 3.6
+      env: TOX_ENV=py36-django30
+    - python: 3.7
+      env: TOX_ENV=py37-django30
 
 install:
   - pip install tox

netfields/compat.py

@@ -0,0 +1,8 @@
+from django import VERSION
+
+if VERSION[0] <= 2:
+    from django.db.backends.postgresql_psycopg2.base import DatabaseWrapper
+    from django.utils.six import with_metaclass, text_type
+else:
+    from django.db.backends.postgresql.base import DatabaseWrapper
+    from six import with_metaclass, text_type

netfields/fields.py

@@ -1,20 +1,11 @@
 from django.core.exceptions import ValidationError
 from django.db import models
 
-from django import VERSION
-
-if VERSION[0] <= 2:
-    from django.db.backends.postgresql_psycopg2.base import DatabaseWrapper
-    from django.utils.six import with_metaclass, text_type
-else:
-    from django.db.backends.postgresql.base import DatabaseWrapper
-    from six import with_metaclass, text_type
-
-from django.utils.six import with_metaclass, text_type
 from ipaddress import ip_interface, ip_network
 from netaddr import EUI
 from netaddr.core import AddrFormatError
 
+from netfields.compat import DatabaseWrapper, with_metaclass, text_type
 from netfields.forms import InetAddressFormField, CidrAddressFormField, MACAddressFormField
 from netfields.mac import mac_unix_common
 from netfields.psycopg2_types import Inet, Macaddr

netfields/forms.py

@@ -2,9 +2,9 @@
 from netaddr import EUI, AddrFormatError
 
 from django import forms
-from django.utils.six import text_type
 from django.core.exceptions import ValidationError
 
+from netfields.compat import text_type
 from netfields.mac import mac_unix_common
 
 

netfields/rest_framework.py

@@ -1,11 +1,11 @@
 from __future__ import absolute_import
 
-from django.utils.six import text_type
 from ipaddress import ip_interface, ip_network, ip_address
 from netaddr import EUI
 from netaddr.core import AddrFormatError
 from rest_framework import serializers
 
+from netfields.compat import text_type
 from netfields.mac import mac_unix_common
 
 

tox.ini

@@ -31,6 +31,8 @@ envlist=
     py35-django22,
     py36-django22,
     py37-django22,
+    py36-django30,
+    py37-django30,
 
 
 
@@ -327,3 +329,21 @@ deps=
     psycopg2
     djangorestframework
     unittest2
+
+[testenv:py36-django30]
+basepython=python3.6
+deps=
+    django>=3.0,<3.1
+    netaddr
+    psycopg2
+    djangorestframework
+    unittest2
+
+[testenv:py37-django30]
+basepython=python3.7
+deps=
+    django>=3.0,<3.1
+    netaddr
+    psycopg2
+    djangorestframework
+    unittest2