add ruff linter and refactor all code

main.py

@@ -1,16 +1,20 @@
 import asyncio
 from datetime import datetime, timedelta
 
-from aiogram import Dispatcher, Bot, F
+import environs
+from aiogram import Bot, Dispatcher, F
 from aiogram.client.default import DefaultBotProperties
 from aiogram.enums import ParseMode
 from aiogram.filters import Command
 from aiogram.types import Message
-import environs
 
+from additional_functions import (
+    on_notification,
+    set_group,
+    timetable_day,
+    timetable_for_day,
+)
 from DB import UseDB
-from additional_functions import (on_notification, set_group, timetable_for_day,
-                                  timetable_day)
 from use_database import detect_group_to_update
 
 env = environs.Env()
@@ -20,7 +24,7 @@ dp = Dispatcher()
 
 
 @dp.message(Command("start"))
-async def start_handler(msg: Message):
+async def command_start(msg: Message):
     await msg.answer(
         "Приветствую!\nЭтот бот предназначен для просмотра расписания занятий "
         "для любой группы СибГУ, включая сегодня, завтра и послезавтра.\n"
@@ -35,7 +39,7 @@ async def start_handler(msg: Message):
 
 
 @dp.message(Command("set_group"))
-async def start_handler(msg: Message):
+async def command_set_group(msg: Message):
     if len(msg.text.split()) == 2:
         await set_group(msg)
     else:
@@ -46,7 +50,7 @@ async def start_handler(msg: Message):
 
 
 @dp.message(Command("on_notification"))
-async def start_handler(msg: Message):
+async def command_on_notification(msg: Message):
     if len(msg.text.split()) == 2:
         await on_notification(msg)
     else:
@@ -58,19 +62,19 @@ async def start_handler(msg: Message):
 
 @dp.message(F.text == "сегодня")
 @dp.message(Command("today"))
-async def start_handler(msg: Message):
+async def command_today(msg: Message):
     await timetable_for_day(msg)
 
 
 @dp.message(F.text == "завтра")
 @dp.message(Command("tomorrow"))
-async def start_handler(msg: Message):
+async def command_tomorrow(msg: Message):
     await timetable_for_day(msg, 1)
 
 
 @dp.message(F.text == "послезавтра")
 @dp.message(Command("the_day_after_tomorrow"))
-async def start_handler(msg: Message):
+async def command_the_day_after_tomorrow(msg: Message):
     await timetable_for_day(msg, 2)
 
 
@@ -107,5 +111,6 @@ async def main() -> None:
     _ = asyncio.create_task(update_data())
     await dp.start_polling(bot)
 
+
 if __name__ == "__main__":
     asyncio.run(main())