SQLAlchemy Session.add doesn't work?

Question

I have a strange error using Python 3.3.0 and SQLAlchemy 0.8.0:

from sqlalchemy import create_engine, Integer, String, Text, Column, Sequence, DateTime, ForeignKey
from sqlalchemy.orm import sessionmaker, relationship, backref
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine("sqlite:///:memory:", echo=True)
Session = sessionmaker(bind = engine)
Base = declarative_base()

class Product(Base):
    __tablename__ = "products"

    id = Column(Integer, primary_key=True)
    name = Column(String(200))
    description = Column(Text)

Base.metadata.create_all(engine)

session = Session()
product = Product()
product.id = 1
product.name = "Test"
product.description = "Test"

session.add(product)
print(product in session) # Expected true
session.commit()
print(session.query(Product).all()) # Expected the previous item

As commented in code I expected the add method to add the product to the database using an INSERT. But it doesn't nor does it throw an exception. This is the log:

2013-04-16 18:03:14,368 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("products")
2013-04-16 18:03:14,369 INFO sqlalchemy.engine.base.Engine ()
2013-04-16 18:03:14,371 INFO sqlalchemy.engine.base.Engine 
CREATE TABLE products (
    id INTEGER NOT NULL, 
    name VARCHAR(200), 
    description TEXT, 
    PRIMARY KEY (id)
)


2013-04-16 18:03:14,371 INFO sqlalchemy.engine.base.Engine ()
2013-04-16 18:03:14,371 INFO sqlalchemy.engine.base.Engine COMMIT
False
2013-04-16 18:04:04,706 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2013-04-16 18:04:04,708 INFO sqlalchemy.engine.base.Engine SELECT products.id AS products_id, products.name AS products_name, products.description AS products_description 
FROM products
2013-04-16 18:04:04,709 INFO sqlalchemy.engine.base.Engine ()
[]

I already tried several things:

• Changing the engine doesn't work. I also tried postgresql.
• I tried debugging. When I reach the body of the add method there is nothing to step into.

Am I doing something wrong or is this a bug?

Answer 1

This problem appears to be a Python version specific problem. Using Python 3.3.1 solves the problem.