[CentralOH] __metaclass__

Mark Erbaugh mark at microenh.com
Thu Jun 26 18:13:07 CEST 2008

I've discovered something strange with some Python 2.4.3 code that I'm
working on.

I have a class, Query, that sets __metaclass__.  The class is designed
to be derived from and children of this class have been working.

This morning, I created a new child class, but I also named it Query

import query_base as Q

class Query(Q.Query):

The class didn't work and upon investigation, it looks like the
metaclass is not being used.  IOW, once the instance is created,
<instance>.__metaclass_ returns None

However, if I change the name of the class to something else, everything
works and <instance>.__metaclass__ has the expected value.

It looks like Python or I are violating a namespace somewhere.

Obviously, the immediate solution is to not re-use the name, but that
happens to be a very good name for the class. 

I'm really more interested in understanding what's actually going on.

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