вот что я делал

можете подсказать откуда вы такую информацию знаете

это что за обрывок скриншота?

формально такого быть не должно, поскольку в его коде явного переиспользования сессии нет, а алхимия использует NullPool и соответственно новое соединение для каждого потока.

а где ты нашел NullPool?

да вот там же по ссылке выше от печеньки

When a file-based database is specified, the dialect will use NullPool as the source of connections.

ну это голая алхимия если

хорошо если нету

Traceback (most recent call last):
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 774, in _commit_impl
   self.engine.dialect.do_commit(self.connection)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\default.py", line 543, in do_commit
   dbapi_connection.commit()
sqlite3.ProgrammingError: SQLite objects created in a thread can only be used in that same thread. The object was created in thread id 5776 and this is thread id 10132.
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
 File "<input>", line 1, in <module>
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\orm\scoping.py", line 163, in do
   return getattr(self.registry(), name)(*args, **kwargs)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\orm\session.py", line 1042, in commit
   self.transaction.commit()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\orm\session.py", line 508, in commit
   t[1].commit()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1771, in commit
   self._do_commit()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1802, in _do_commit
   self.connection._commit_impl()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 776, in _commit_impl
   self._handle_dbapi_exception(e, None, None, None, None)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1517, in _handle_dbapi_exception
   util.raise_(
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\util\compat.py", line 178, in raise_
   raise exception
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 774, in _commit_impl
   self.engine.dialect.do_commit(self.connection)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\default.py", line 543, in do_commit
   dbapi_connection.commit()
sqlalchemy.exc.ProgrammingError: (sqlite3.ProgrammingError) SQLite objects created in a thread can only be used in that same thread. The object was created in thread id 5776 and this is thread id 10132.
(Background on this error at: http://sqlalche.me/e/f405)base.py", line 774, in _commit_impl
   self.engine.dialect.do_commit(self.connection)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\default.py", line 543, in do_commit
   dbapi_connection.commit()
sqlite3.ProgrammingError: SQLite objects created in a thread can only be used in that same thread. The object was created in thread id 5776 and this is thread id 10132.
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
 File "<input>", line 1, in <module>
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\orm\scoping.py", line 163, in do
   return getattr(self.registry(), name)(*args, **kwargs)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\orm\session.py", line 1042, in commit
   self.transaction.commit()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\orm\session.py", line 508, in commit
   t[1].commit()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1771, in commit
   self._do_commit()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1802, in _do_commit
   self.connection._commit_impl()
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 776, in _commit_impl
   self._handle_dbapi_exception(e, None, None, None, None)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 1517, in _handle_dbapi_exception
   util.raise_(
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\util\compat.py", line 178, in raise_
   raise exception
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\base.py", line 774, in _commit_impl
   self.engine.dialect.do_commit(self.connection)
 File "C:\IT\P_Y\flaskblog2\venv\lib\site-packages\sqlalchemy\engine\default.py", line 543, in do_commit
   dbapi_connection.commit()
sqlalchemy.exc.ProgrammingError: (sqlite3.ProgrammingError) SQLite objects created in a thread can only be used in that same thread. The object was created in thread id 5776 and this is thread id 10132.
(Background on this error at: http://sqlalche.me/e/f405)

вот что я делал