Python 3.7 compatibility issue fix (#12)

Fixed python 3.7 compatibility
Removed Python 3.3 support as psycopg2 doesn't support it any more
Moved testing to xenial release to support python 3.7

.travis.yml

@@ -1,11 +1,10 @@
-dist: trusty
+dist: xenial
 sudo: false
 language: python
 cache: pip
 
 python:
   - 2.7
-  - 3.3
   - 3.4
   - 3.5
   - 3.6
@@ -28,16 +27,8 @@ matrix:
   - python: 2.7
     env: DJANGO=2.1
 
-  # Django 1.9+ doesn't support python 3.3
-  - python: 3.3
-    env: DJANGO=1.9
-  - python: 3.3
-    env: DJANGO=1.10
-  - python: 3.3
-    env: DJANGO=1.11
-  - python: 3.3
-    env: DJANGO=2.0
-  - python: 3.3
+  # Django 2.1 doesn't support python 3.4
+  - python: 3.4
     env: DJANGO=2.1
 
   # Django 1.7 doesn't support python 3.5+
@@ -48,6 +39,21 @@ matrix:
   - python: 3.7
     env: DJANGO=1.7
 
+  # python 3.6 has deprecated issue with django before 1.11
+  # https://stackoverflow.com/questions/41343263/provide-classcell-example-for-python-3-6-metaclass\
+  - python: 3.6
+    env: DJANGO=1.8
+  - python: 3.6
+    env: DJANGO=1.9
+  - python: 3.6
+    env: DJANGO=1.10
+  - python: 3.7
+    env: DJANGO=1.8
+  - python: 3.7
+    env: DJANGO=1.9
+  - python: 3.7
+    env: DJANGO=1.10
+
 install:
   - pip install -r requirements.txt
   - pip install -q Django==$DJANGO

README.md

@@ -2,7 +2,7 @@
 Extended form fields to validate REST-request data via django.forms.
 
 ## Requirements
-* Python 2.7 or Python 3.3+
+* Python 2.7 or Python 3.4+
 * Django >= 1.7
 * pytz
 * jsonschema

requirements.txt

@@ -4,3 +4,4 @@ jsonschema
 six
 typing
 psycopg2
+typing

setup.py

@@ -13,7 +13,7 @@
 
 setup(
     name='django-rest-form-fields',
-    version='1.2.7',
+    version='1.2.8',
     packages=['django_rest_form_fields'],
     package_dir={'': 'src'},
     url='https://github.com/M1hacka/django-rest-form-fields',

src/django_rest_form_fields/compatibility.py

@@ -2,8 +2,9 @@
 This file contains functions for different python and django version compatibility
 """
 import datetime
-
 import pytz
+import re
+
 from django.utils.timezone import make_aware, utc
 
 
@@ -18,3 +19,7 @@ def to_timestamp(dt):  # type: (datetime.datetime) -> float
         return dt.timestamp()
     else:
         return (dt - datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=pytz.utc)).total_seconds()
+
+
+def get_pattern_type():
+    return re.Pattern if hasattr(re, 'Pattern') else re._pattern_type

src/django_rest_form_fields/fields.py

@@ -17,8 +17,8 @@
 from django.utils.timezone import make_aware, utc
 from typing import Any, Optional, Union
 
-from django_rest_form_fields.compatibility import to_timestamp
-from django_rest_form_fields.exceptions import FileSizeError, FileTypeError
+from .compatibility import to_timestamp, get_pattern_type
+from .exceptions import FileSizeError, FileTypeError
 
 
 class BaseField(forms.Field):
@@ -98,7 +98,7 @@ def __init__(self, *args, **kwargs):
         self.regex = kwargs.pop('regex', None)
         self.flags = kwargs.pop('flags', 0)
 
-        assert self.regex is None or isinstance(self.regex, (six.string_types, re._pattern_type)),\
+        assert self.regex is None or isinstance(self.regex, (six.string_types, get_pattern_type())),\
             'regex must be string if given'
         assert isinstance(self.flags, int), 'flags must be integer'