Icebreaker454/main.py

## main.py
import asyncio
import sqlalchemy as sa
from sqlalchemy import select

from sqlalchemy.ext.declarative import declarative_base, declared_attr
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession

postgresql_url = "postgresql+asyncpg://localhost:5432/test_sqlalchemy_db"

engine = create_async_engine(postgresql_url, echo=True)


class CustomBase:
    @declared_attr
    def __tablename__(cls):  # noqa
        return cls.__name__.lower()

    @declared_attr
    def id(cls):  # noqa
        return sa.Column(sa.Integer, primary_key=True)


Base = declarative_base(cls=CustomBase)


class User(Base):
    username = sa.Column(sa.String)
    email = sa.Column(sa.String)


async def main():

    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)

    async with AsyncSession(engine) as session:
        async with session.begin():
            user = User(username="john_smith")
            session.add(user)

        # Here we re-fetch the same user
        stmt = select(User).filter_by(username="john_smith")
        cursor = await session.execute(stmt)
        user = cursor.scalar()

        # Modify some attrs
        user.email = "jsmith@gmail.com"

        await session.commit()

        # Here goes the greenlet_spawn issue
        print(user.username)

    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)


if __name__ == '__main__':
    asyncio.run(main())
	import asyncio
	import sqlalchemy as sa
	from sqlalchemy import select

	from sqlalchemy.ext.declarative import declarative_base, declared_attr
	from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession

	postgresql_url = "postgresql+asyncpg://localhost:5432/test_sqlalchemy_db"

	engine = create_async_engine(postgresql_url, echo=True)


	class CustomBase:
	@declared_attr
	def __tablename__(cls): # noqa
	return cls.__name__.lower()

	@declared_attr
	def id(cls): # noqa
	return sa.Column(sa.Integer, primary_key=True)


	Base = declarative_base(cls=CustomBase)


	class User(Base):
	username = sa.Column(sa.String)
	email = sa.Column(sa.String)


	async def main():

	async with engine.begin() as conn:
	await conn.run_sync(Base.metadata.create_all)

	async with AsyncSession(engine) as session:
	async with session.begin():
	user = User(username="john_smith")
	session.add(user)

	# Here we re-fetch the same user
	stmt = select(User).filter_by(username="john_smith")
	cursor = await session.execute(stmt)
	user = cursor.scalar()

	# Modify some attrs
	user.email = "jsmith@gmail.com"

	await session.commit()

	# Here goes the greenlet_spawn issue
	print(user.username)

	async with engine.begin() as conn:
	await conn.run_sync(Base.metadata.drop_all)


	if __name__ == '__main__':
	asyncio.run(main())