diff --git a/telebot/__init__.py b/telebot/__init__.py
index bb48123..b13c396 100644
--- a/telebot/__init__.py
+++ b/telebot/__init__.py
@@ -359,10 +359,7 @@ class TeleBot:
         :return: array of Updates
         """
         json_updates = apihelper.get_updates(self.token, offset, limit, timeout, allowed_updates, long_polling_timeout)
-        ret = []
-        for ju in json_updates:
-            ret.append(types.Update.de_json(ju))
-        return ret
+        return [types.Update.de_json(ju) for ju in json_updates]
 
     def __skip_updates(self):
         """
@@ -832,10 +829,7 @@ class TeleBot:
         :return:
         """
         result = apihelper.get_chat_administrators(self.token, chat_id)
-        ret = []
-        for r in result:
-            ret.append(types.ChatMember.de_json(r))
-        return ret
+        return [types.ChatMember.de_json(r) for r in result]
 
     def get_chat_members_count(self, chat_id: Union[int, str]) -> int:
         """
@@ -1307,10 +1301,7 @@ class TeleBot:
         result = apihelper.send_media_group(
             self.token, chat_id, media, disable_notification, reply_to_message_id, timeout, 
             allow_sending_without_reply)
-        ret = []
-        for msg in result:
-            ret.append(types.Message.de_json(msg))
-        return ret
+        return [types.Message.de_json(msg) for msg in result]
 
     def send_location(
             self, chat_id: Union[int, str], 
@@ -1962,10 +1953,7 @@ class TeleBot:
         :return:
         """
         result = apihelper.get_game_high_scores(self.token, user_id, chat_id, message_id, inline_message_id)
-        ret = []
-        for r in result:
-            ret.append(types.GameHighScore.de_json(r))
-        return ret
+        return [types.GameHighScore.de_json(r) for r in result]
 
     def send_invoice(
             self, chat_id: Union[int, str], title: str, description: str, 
diff --git a/telebot/types.py b/telebot/types.py
index b0ccae9..8dba5cc 100644
--- a/telebot/types.py
+++ b/telebot/types.py
@@ -81,13 +81,10 @@ class JsonDeserializable(object):
             raise ValueError("json_type should be a json dict or string.")
 
     def __str__(self):
-        d = {}
-        for x, y in self.__dict__.items():
-            if hasattr(y, '__dict__'):
-                d[x] = y.__dict__
-            else:
-                d[x] = y
-
+        d = {
+            x: y.__dict__ if hasattr(y, '__dict__') else y
+            for x, y in self.__dict__.items()
+        }
         return str(d)
 
 
diff --git a/telebot/util.py b/telebot/util.py
index 711f003..34d08ed 100644
--- a/telebot/util.py
+++ b/telebot/util.py
@@ -351,9 +351,10 @@ def quick_markup(values: Dict[str, Dict[str, Any]], row_width: int=2) -> types.I
     :return: InlineKeyboardMarkup
     """
     markup = types.InlineKeyboardMarkup(row_width=row_width)
-    buttons = []
-    for text, kwargs in values.items():
-        buttons.append(types.InlineKeyboardButton(text=text, **kwargs))
+    buttons = [
+        types.InlineKeyboardButton(text=text, **kwargs)
+        for text, kwargs in values.items()
+    ]
     markup.add(*buttons)
     return markup