By default, SqlAlchemy has `expire_on_commit=True`. I'm going to poorly restate most of what Mike Bayer has told me in the past: the rationale behind this- an active Session is supposed to mirror the current state in the database; within a transaction we know the object values are equal to the table values. Once the transaction ends via `commit`, the object is no longer in sync - another transaction may have modified that database row.
In your example, note these 2 lines from the stacktrace: File "sqlalchemy/orm/attributes.py", line 669, in get value = state._load_expired(state, passive) when you invoked a `commit`, SqlAlchemy expired the object (after the commit). when you invoked `print()`, SqlAclhemy recognized the object as expired and is now trying to load the expired attributes so it can print them for you. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/bdb5dde6-ff15-472d-a3da-4aa5b980fdfc%40googlegroups.com.
