'NoneType' object has no attribute '_autoflush' in SQLAlchemy Query().filter_by().all() object

Question

having trouble in sqlAlchemy query when getting all data from table it raise error when i use .all() mathod

here is error:

File "./individual/admin/handler.py", line 69, in test_account_indiv
    query = Query(User).filter_by(account_type="INDIVIDUAL", is_deleted=0).all()
  File "/home/awaiskaleem/Documents/backend-api-develop/venv/lib/python3.8/site-packages/sqlalchemy/orm/query.py", line 3341, in all
    return list(self)
  File "/home/awaiskaleem/Documents/backend-api-develop/venv/lib/python3.8/site-packages/sqlalchemy/orm/query.py", line 3502, in __iter__
    self.session._autoflush()
**AttributeError: 'NoneType' object has no attribute '_autoflush'**

here is code:

query = Query(User).filter_by(account_type="INDIVIDUAL", is_deleted=0).all()

rows = query.with_session(session)

    only = ("id", "full_name", "status", "default_address.id", "default_address.region.id",
            "default_address.region.name", "tags.tag", "tags.hex_color",
            "assigned_region_workers.region_worker.worker.id",
            "assigned_region_workers.region_worker.worker.full_name")

    schema = UserSchema(only=only, many=True)

    result = schema.dump(rows)

here is connection:

session_maker = sessionmaker()

USER = os.getenv('DB_USER')
PASSWORD = os.getenv('DB_PASSWORD')
URL = os.getenv('DB_URL')
DB = os.getenv('DB_NAME')

try:
    logger.info("Attempting connect to: mysql+pymysql://%s:%s@%s/%s", USER, PASSWORD, URL, DB)
    engine = create_engine("mysql+pymysql://%s:%s@%s/%s" % (USER, PASSWORD, URL, DB), pool_size=1)
    engine.connect()
    logger.info("Connected to: mysql+pymysql://%s:%s@%s/%s", USER, PASSWORD, URL, DB)
    
except SQLAlchemyError as error:
    logger.error("Error connecting to DB")
    logger.error(error)
else:
    session_maker.configure(bind=engine)

Session = session_maker()

i am developing AWS Lembda based Serverless Project on localhost with MySQL databse and SQLAlchemy ORM model everything is setup on virtual envirnment using dockers in ubuntu

plz help me thanks for advance

looking foreword for positive response