It's on SO's Python FAQ too. This is the only thing in Python that's really bitten me. I remember it took me like a week to figure this out when I was tearing d

It's on SO's Python FAQ too. This is the only thing in Python that's really bitten me. I remember it took me like a week to figure this out when I was tearing down my algorithm bit by bit to find out whether my prove was wrong or the code. http://stackoverflow.com/questions/1132941/least-astonishment-in-python-the-mutable-default-argument http://stackoverflow.com/questions/1132941/least-astonishmen...