[Tutor] Optional parameter passing

[wormwood_3]

You know, that's a great idea :-)  Just using options I could keep my initial checks the same (e.g. making sure needed options were included by looking at options.foo) and pass it along without adding much to the query function.

Thanks!

 _______________________
Samuel Huckins


Homepage - http://samuelhuckins.com
Tech blog - http://dancingpenguinsoflight.com/
Photos - http://www.flickr.com/photos/samuelhuckins/
AIM - samushack | Gtalk - samushack | Skype - shuckins




________________________________
From: Kent Johnson <kent37 at tds.net>
To: wormwood_3 <wormwood_3 at yahoo.com>
Cc: Python Tutorlist <tutor at python.org>
Sent: Monday, January 12, 2009 5:09:31 PM
Subject: Re: [Tutor] Optional parameter passing

On Mon, Jan 12, 2009 at 4:39 PM, wormwood_3 <wormwood_3 at yahoo.com> wrote:
> Hello all,
>
> I have used *args and **kwargs to have a function accept optional
> parameters, but is there a lazy way to optionally pass parameters? For
> example, say my script can accept a number of parameters for a database
> connection, such as user, password, and database name. The function that
> makes the MySQL call has a default for user, say "root". So if the user
> didn't pass in a value for the user option, I don't want to pass it to the
> function doing the MySQL call. I don't want to have to do:
>
> if options.user:
>     do_mysql_query(user)
> else:
>     do_mysql_query()
>
> and so on for each possible option. Is there a better way?

You would have to put the options into a collection, a list or dict or
class. You can use *args and **kwargs at the point of call as well as
in a function definition.

What about having the defaults in the options object and just passing
it to the function?
  do_mysql_query(options)

or pass the options and have the function use code like
  user = options.user or 'root'

Kent
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/tutor/attachments/20090112/314e14d2/attachment.htm>