Fix failure due to Python3.8 Enum behavior

- Update tox, to cover Django versions `3.0.*` and `3.1.*`
- Limit DRF version for Django 1 support
- Exclude some random folders from `flake8`

django_enum_choices/fields.py

@@ -139,12 +139,24 @@ def validate(self, value, *args, **kwargs):
         if not self.blank and value in self.empty_values:
             raise ValidationError(self.error_messages['blank'], code='blank')
 
-        if value not in self.enum_class:
-            raise ValidationError(
-                self.error_messages['invalid_choice'],
-                code='invalid_choice',
-                params={'value': value}
-            )
+        enum_value = value
+
+        if not isinstance(enum_value, self.enum_class):
+            try:
+                enum_value = self.to_enum_value(value)
+
+                if enum_value not in self.enum_class:
+                    raise ValidationError(
+                        self.error_messages['invalid_choice'],
+                        code='invalid_choice',
+                        params={'value': value}
+                    )
+            except ValidationError:
+                raise ValidationError(
+                    self.error_messages['invalid_choice'],
+                    code='invalid_choice',
+                    params={'value': value}
+                )
 
     def value_to_string(self, obj):
         value = self.value_from_object(obj)

django_enum_choices/forms.py

@@ -42,4 +42,4 @@ def prepare_value(self, value):
         return value
 
     def valid_value(self, value):
-        return value in self.enum_class
+        return isinstance(value, self.enum_class) and value in self.enum_class

setup.cfg

@@ -6,5 +6,4 @@ commit = True
 
 [flake8]
 max-line-length = 120
-exclude = .tox,.git,*/migrations/*,*/static/CACHE/*,docs,node_modules,*/settings/*,.venv,*/e2e/e2e/*
-
+exclude = .tox,.git,*/migrations/*,*/static/CACHE/*,docs,node_modules,*/settings/*,.venv,*/e2e/*

tox.ini

@@ -1,13 +1,17 @@
 [tox]
 envlist =
-    lint-py{37}
-    django22-py{37,36}
-    django21-py{37,36,35}
-    django111-py{37,36,35}
+    lint-py{37,38}
+    django31-py{38,37,36}
+    django30-py{38,37,36}
+    django22-py{38,37,36}
+    django21-py{38,37,36,35}
+    django111-py{38,37,36,35}
 
 [testenv]
 deps =
     {[base]deps}
+    django31: {[django]3.1}
+    django30: {[django]3.0}
     django22: {[django]2.2}
     django21: {[django]2.1}
     django111: {[django]1.11}
@@ -20,6 +24,11 @@ deps =
     flake8
 commands = flake8 django_enum_choices/
 
+[testenv:lint-py38]
+deps =
+    flake8
+commands = flake8 django_enum_choices/
+
 [base]
 deps =
     pytest
@@ -29,8 +38,16 @@ deps =
     psycopg2
 
 [django]
+3.1 =
+    Django>=3.1.0,<3.2.0
+    djangorestframework>=3.7.3
+    django-filter>=2.2.0
+3.0 =
+    Django>=3.0.0,<3.1.0
+    djangorestframework>=3.7.3
+    django-filter>=2.2.0
 2.2 =
-    Django>=2.2.0,<2.3.0
+    Django>=2.2.0,<2.2.17
     djangorestframework>=3.7.3
     django-filter>=2.2.0
 2.1 =
@@ -39,5 +56,5 @@ deps =
     django-filter>=2.2.0
 1.11 =
     Django>=1.11.0,<2.0.0
-    djangorestframework>=3.6.2
-    django-filter>=2.2.0
+    djangorestframework>=3.6.2,<3.9.0
+    django-filter>=2.2.0