file object as container class

[Matthew Wilson]

I have a bunch of classes that track data for time series.  The classes are
really just glorified dicts where the key is a date object, and the value is the
value as of that date.

I want a way to store a bunch of these tseries objects into a file object.  I
want to be able to open the file object, iterate through all timeseries, then
create some new tseries, and add them to the file object.  I also want to be
able to delete tseries from the file object.

Can anyone give me any pointers on how to write a file object like this?