sqlobject-discuss

[SQLObject] How do I find this?

[Iwan V. <iw...@re...>]

Hi there.  

We are struggling with a bug which I am not sure how to track down
further.  This may not be related to sqlobject, but sqlobject is where
the trail starts.

We have a set of tests which ran fine previously - when separate test
runs used to happen in separate processes. Now, however, we run more
test runs together in the same process and get a breakage that does not
make sense.  Any pointers as to how we should hunt this thing down would
be appreciated:

The breakage happens in sqlobject's col.py, in method to_python of
DecimalValidator.  The method gets called with a value which is an
instance of a decimal.Decimal class, yet the code gets through to the
try: statement right at the end of the function.  (It should have been
caught earlier.)  The reason it is not caught earlier is because (from
pdb):

(Pdb) value.__class__
<class 'decimal.Decimal'>

And yet:
(Pdb) value.__class__ is Decimal
False

Seems like the imported Decimal and the Decimal of which value is an
instance are not the same thing.

Specifically, the imported Decimal seems to the the "right" one, since:
(Pdb) Decimal is getattr(sys.modules['decimal'],'Decimal')
True

Where does the Decimal class come from, of which value is an instance?
Does sqlobject do anything funny when constructing these?  Or should I
look beyond sqlobject?  

(We're using postgresql 8.3 and psycopg2 also.)

Thanks
- Iwan Vosloo

Re: [SQLObject] How do I find this?

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

On Mon, Mar 30, 2009 at 05:00:42PM +0200, Iwan Vosloo wrote:
> (Pdb) value.__class__
> <class 'decimal.Decimal'>
> 
> And yet:
> (Pdb) value.__class__ is Decimal
> False
> 
> Seems like the imported Decimal and the Decimal of which value is an
> instance are not the same thing.
> 
> Specifically, the imported Decimal seems to the the "right" one, since:
> (Pdb) Decimal is getattr(sys.modules['decimal'],'Decimal')
> True
> 
> Where does the Decimal class come from, of which value is an instance?

   Pretty normal situations that manipulate with sys.path. One can easily
imports a module two times:

>>> import sys, os, decimal
>>> decimal.__file__
'/usr/lib/python2.5/decimal.pyc'
>>> os.chdir('/usr/lib/python2.5')
>>> sys.path.insert(0, '.')
>>> del sys.modules['decimal']
>>> import decimal as decimal2
>>> decimal2.__file__
'./decimal.pyc'
>>> decimal.Decimal is decimal2.Decimal
False

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

Re: [SQLObject] How do I find this?

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

On Mon, Mar 30, 2009 at 07:14:52PM +0400, Oleg Broytmann wrote:
>    Pretty normal situations that manipulate with sys.path.

   Sorry, that should be

"Pretty normal situations *in programs* that manipulate with sys.path."

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