Design tips requested for OOP forum system (using pickle)

[Andy Todd]

"Graham Ashton" <graz at mindless.com> wrote in <56zN7.139$Jm.5630 at stones>:

>In article <eb8b2b6e.0111291359.64a1ee62 at posting.google.com>, "Simon
>Willison" <cs1spw at bath.ac.uk> wrote:
>
>> I'm something of a Python newbie but I'm keen to learn so I've decided
>> to throw myself in at the deep end.
>
>Good plan. The fastest way to learn, I reckon.
>
>> Anyway - I've decided to code a flat threaded web forum system ... using
>> pickled objects in flat files to store the data (rather than using a
>> database or a delimited flat file format of some sort).
>
>Here's an idea to think about; see if you can work out how to design a
>fairly generic interface to your storage. Implement it first with pickle
>(cPickle is much faster by the way) and then see if you can fiddle around
>with it a bit so that it supports different storage systems (e.g. anydbm),
>selectable at run time. Design patterns will be your friend here, and are
>very interesting ways of taking your OOD knowledge beyond the standard
>inheritance and delegation techniques.

If your interface is generic enough it is but a small step from pickle to 
database type storage (either an object database like ZODB or a relational 
database). 

>
>Top pickle tip (cPickle isn't available everywhere):
>
>  try:
>      import cPickle
>      pickle = cPickle
>  except ImportError:
>      import pickle

Let me save you a whole line of code here;

    try:
        import cPickle as pickle
    except ImportError:
        import pickle

>
[snip some great tips and hints]
>

For what it is worth, you will probably end up needing a fast efficient 
database server to store your data in. I know you are building this project 
as a learning exercise but consider porting the data storage of your 
(nearly) finished version to something like MySQL or PostgreSQL as an 
exercise in OO <-> RDBMS mapping. That one can twist even the finest minds 
into knots ;-)


Regards,
Andy
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