Easy representation of data object in SQLAlchemy with BaseExt

baseextsnippet.py

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


engine = create_engine('mysql://user:pass@localhost/databasename')

# Found: http://www.mail-archive.com/[email protected]/msg18049.html
class BaseExt(object):
     """Does much nicer repr/print of class instances
     from sqlalchemy list suggested by Michael Bayer
     """
     def __repr__(self):
         return "%s(%s)" % (
                  (self.__class__.__name__),
                  ', '.join(["%s=%r" % (key, getattr(self, key))
                             for key in sorted(self.__dict__.keys())
                             if not key.startswith('_')]))

Base = declarative_base(cls=BaseExt)

# Declare tables as usual...

class Packages(Base):
    __tablename__ = 'hosts'
    id = Column(Integer, primary_key=True)
    name = Column(String(250))
    version = Column(String(250))
    arch = Column(String(20))

Session = sessionmaker(bind=engine)
session = Session()

for package in session.query(Packages).all():
    print package

# Before: <__main__.Packages object at 0x2895ed0>
# After: Packages(arch='amd64', host_id=1L, id=1L, name='apache2', version='2.2')