refactor: TT-353 Solving requested changes on PR

V2/source/daos/activities_json_dao.py

@@ -1,34 +1,31 @@
 from V2.source.daos.activities_dao import ActivitiesDao
 from V2.source.dtos.activity import Activity
+import dataclasses
 import json
 import typing
 
 
 class ActivitiesJsonDao(ActivitiesDao):
     def __init__(self, json_data_file_path: str):
         self.json_data_file_path = json_data_file_path
-        self.activity_keys = Activity.__dataclass_fields__.keys()
+        self.activity_keys = [
+            field.name for field in dataclasses.fields(Activity)
+        ]
 
     def get_by_id(self, activity_id: str) -> Activity:
-        activities_grouped_by_id = {
+        activity = {
             activity.get('id'): activity
             for activity in self.__get_activities_from_file()
-        }
-        activity = activities_grouped_by_id.get(activity_id)
-        activity_dto = (
-            self.__create_activity_dto(activity) if activity else None
-        )
+        }.get(activity_id)
 
-        return activity_dto
+        return self.__create_activity_dto(activity) if activity else None
 
     def get_all(self) -> typing.List[Activity]:
-        all_activities = self.__get_activities_from_file()
-        activity_dtos = [
-            self.__create_activity_dto(activity) for activity in all_activities
+        return [
+            self.__create_activity_dto(activity)
+            for activity in self.__get_activities_from_file()
         ]
 
-        return activity_dtos
-
     def __get_activities_from_file(self) -> typing.List[dict]:
         try:
             file = open(self.json_data_file_path)