In [3]: a=DBSession.query(Page).first()

In [4]: a.__dict__
Out[4]: 
{'_sa_instance_state': <sqlalchemy.orm.identity.IdentityManagedState object at 0x986348c>,
 'data': u'initial data',
 'id': 1,
 'pagename': u'FrontPage'}
In [5]: help(a)

In [6]: b = Page('second pagetitle', 'SecondPage of WikiWords wiki')

In [7]: DBSession.add(b)

In [8]: pages=DBSession.query(Page).all()

In [9]: [(page.data, page.pagename, page.id) for page in pages]
Out[9]: 
[(u'initial data', u'FrontPage', 1),
 ('SecondPage of WikiWords wiki', 'second pagetitle', 2)]
