Re: [SQLObject] default empty dict for picklecol

[Oleg B. <ph...@ph...>]

On Sun, Jan 25, 2009 at 08:35:03PM -0800, Daniel Fetchinson wrote:
> When using a PickleCol with default={ } the behaviour is not exactly
> what I would expect:
> 
> ######################################################################
> from sqlobject import *
> sqlhub.processConnection = connectionForURI( 'sqlite:///:memory:', debug=True )
> class t( SQLObject ):
>     x = PickleCol( default={} )
> t.createTable( )
> row = t( )
> print row.x   # this will print None
> ######################################################################
> 
> Having a non-empty dict works as expected though. I had a feeling it
> was related to mutable keyword argument values and the associated
> problems, but the same problem is there with an empty tuple which is
> certainly unmutable.
> 
> Is this a bug or a feature?

   Seems like a bug related to boolean testing of objects. I.e., somewhere
there is a code that does

if object:...

   instead of

if object is None:...

   But a quick glance at PickleCol code didn't reveal a clue.

Oleg.
-- 
     Oleg Broytmann            http://phd.pp.ru/            ph...@ph...
           Programmers don't die, they just GOSUB without RETURN.