replaced status code using rest_framework, improved code

Author: Inessa Druzhkova

src/django/api/exceptions.py

@@ -1,14 +1,15 @@
 from rest_framework.exceptions import APIException
+from rest_framework import status
 
 
 class BadRequestException(APIException):
-    status_code = 400
+    status_code = status.HTTP_400_BAD_REQUEST
     default_detail = 'Bad request'
     default_code = 'bad_request'
 
 
 class ServiceUnavailableException(APIException):
-    status_code = 503
+    status_code = status.HTTP_503_SERVICE_UNAVAILABLE
     default_detail = 'Service is temporarily unavailable due to maintenance \
         work. Please try again later.'
     default_code = 'service_unavailable'

src/django/api/tests/test_facility_list_create.py

@@ -266,14 +266,11 @@ def test_no_upload_when_disable_list_uploading_switch_active(self):
         self.assertEqual(response.status_code,
                          status.HTTP_503_SERVICE_UNAVAILABLE)
 
-        result = ["".join(json.loads(response.content)['detail'])]
-        # Collapse multiple spaces into one
-        expected = [re.sub(r"\s+", " ", item) for item in expected]
-        stringResult = [re.sub(r"\s+", " ", item) for item in result]
-
+        error_message = json.loads(response.content)['detail']
+        expected_message = " ".join(expected[0].split())
         self.assertEqual(
-            stringResult,
-            expected,
+            " ".join(error_message.split()),
+            expected_message
         )
         self.assertEqual(
             FacilityList.objects.all().count(), previous_list_count