Avoid unnecessary "or 0" in the session classes

telethon/sessions/memory.py

@@ -29,7 +29,7 @@ class MemorySession(Session):
     def __init__(self):
         super().__init__()
 
-        self._dc_id = None
+        self._dc_id = 0
         self._server_address = None
         self._port = None
         self._auth_key = None
@@ -38,7 +38,7 @@ class MemorySession(Session):
         self._entities = set()
 
     def set_dc(self, dc_id, server_address, port):
-        self._dc_id = dc_id
+        self._dc_id = dc_id or 0
         self._server_address = server_address
         self._port = port
 

telethon/sessions/sqlalchemy.py

@@ -129,8 +129,7 @@ class AlchemySession(MemorySession):
             self._auth_key = AuthKey(data=session.auth_key)
 
     def clone(self, to_instance=None):
-        cloned = to_instance or self.__class__(self.container, self.session_id)
-        return super().clone(cloned)
+        return super().clone(MemorySession())
 
     def set_dc(self, dc_id, server_address, port):
         super().set_dc(dc_id, server_address, port)

telethon/sessions/sqlite.py

@@ -198,7 +198,7 @@ class SQLiteSession(MemorySession):
             # multiple DCs. Probably done differently.
             c.execute('delete from sessions')
             c.execute('insert or replace into sessions values (?,?,?,?)', (
-                self._dc_id or 0,
+                self._dc_id,
                 self._server_address,
                 self._port,
                 self._auth_key.key if self._auth_key else b''