Re: Different responses to description request between Mac and Linux

On 3/21/11 7:24 PM, Daniele Varrazzo wrote:
> On Tue, Mar 22, 2011 at 12:51 AM, Jerry Schneider<jerry57@gmail.com>  wrote:
>> I am working on extending a library for RobotFramework and added a keyword
>> for column description retrieval but noticed that when I run it on Mac OS X
>> 10.6 I am getting:
>> Column(name='id', type_code=20, display_size=None, internal_size=8,
>> precision=None, scale=None, null_ok=None)
>> but when I run the exact same test against the exact same database from an
>> Ubuntu 10.10 Linux box I am getting:
>> ('id', 20, None, 8, None, None, None)
>>
>> The only difference that I can find is that the Mac box is running psycopg2
>> 2.4 installed via (python setup.py install) while the Ubuntu box is running
>> psycopg2 2.2.1 installed via package management.  Is it possible that this
>> version difference is what is accounting for the response difference?
> Yes: from 2.4 cursor.description is provided as namedtuple if
> available (http://initd.org/psycopg/docs/cursor.html#cursor.description).
>
> Named tuple are accessible as regular tuple via indexing and hash the
> same, see<http://docs.python.org/library/collections.html#collections.namedtuple>
> so there should be no backward compatibility problem (but if you have
> found any... let's talk about that).
>
> If your concern are doctest (the first thing that comes to mind that
> may have been broken by the namedtuple... but that's because doctests
> are a broken idea) you can use tuple(x) to transform a namedtuple back
> in a regular tuple.
>
> -- Daniele

Thanks Daniele, that is what I needed to know.  No these aren't being
used for doctests, but rather verification tests that the columns are
setup/defined correctly after a database upgrade.  I will adapt the
keyword I was creating using the connections.namedtuple.

jer

--
Jerry Schneider
QA Manager
iPlant Collaborative
BIO5 Research Institute
University of Arizona
Linux registered user #475536
Ubuntu registered user #28583