By trying to access to the class attribute i got an error greenlet_spawn. How i can fix that?

My code example:

import asyncio

from uuid import uuid4
from asyncpg import Connection
from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker, AsyncSession
from sqlalchemy import Column, BigInteger, Pool, String, create_engine
from sqlalchemy.orm import DeclarativeBase, sessionmaker

class CConnection(Connection):
    def _get_unique_id(self, prefix: str) -> str:
        return f"__asyncpg_{prefix}_{uuid4()}"
    

class Base(DeclarativeBase):
    pass


class Message(Base):
    __tablename__ = "message"
    
    id = Column(BigInteger, primary_key=True)
    message = Column(String, nullable=False)
    # ... other cols

class User(Base):
    __tablename__ = "user"
    
    id = Column(BigInteger, primary_key=True)
    username = Column(String)
    # ... other cols

# ... other models

def get_engine(
        database_url: str = None,
        session_name: str = "Unknown",
        pool_size: int = 5,
        max_overflow: int = 0,
        pool_class: Pool = None,
        is_async: bool = False
):
    if is_async:
        return create_async_engine(
            url=database_url,
            poolclass=pool_class,
            pool_size=pool_size,
            max_overflow=max_overflow,
            pool_recycle=3600,
            future=True,
            connect_args={
                "statement_cache_size": 0,
                "prepared_statement_cache_size": 0,
                "connection_class": CConnection,
                "server_settings": {
                    "options": "-c timezone=utc -c statement_timeout=1800000",
                    "application_name": session_name,
                }
            },

        )
    else:
        return create_engine(
            url=database_url,
            pool_recycle=3600,
            poolclass=pool_class,
            pool_size=pool_size,
            max_overflow=max_overflow,
            connect_args={
                "options": "-c timezone=utc -c statement_timeout=1800000",
                "application_name": session_name,
            }

        )


def get_session_maker(engine, is_async: bool = False):
    if is_async:
        return async_sessionmaker(bind=engine, autoflush=False, expire_on_commit=False, class_=AsyncSession)
    else:
        return sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)


def get_session(
        database_url: str = None,
        session_name: str = "Unknown",
        pool_size: int = 3,
        max_overflow: int = 0,
        pool_class: Pool = None,
        is_async: bool = False,
        with_engine: bool = False
):
    engine = get_engine(database_url, session_name, pool_size, max_overflow, pool_class, is_async)
    session = get_session_maker(engine, is_async)

    if with_engine:
        return session(), engine
    else:
        return session()


async def head_main(*args, **kwargs):
    session = get_session("postgresql+asyncpg://postgres:postgres@localhost/exp")
    session_lock = asyncio.Lock()
    queue = asyncio.Queue()
    
    # ... some inner funcs
    
    async def prepare_message():
        if queue.empty():
            return
        
        while not queue.empty():
            async with session_lock:
                message: Message = await queue.get()
                async with session_lock:
                    message.message = _clear_message(message.message)  # error trying to access message attribute
    
    asyncio.gather(
        prepare_message,
        # ... some other funcs
    )

From another sources i got textual data and they processing in different inner functions, and writing to the database.

There’s also a relationship problem. I tried doing joinedload, but still an error(

May be problem in session_lock context?

Exception:

sqlalchemy.exc.MissingGreenlet: greenlet_spawn has not been called; can't call await_only() here. Was IO attempted in an unexpected place? (Background on this error at: https://sqlalche.me/e/20/xd2s)