On Fri, 10 Aug 2001, Charlie Clark wrote:

>  I'd like to use vars() in together with a database command (Marc André 

>  Lemburg's mxODBC) but seem to have missed something.

>  

>  articles = {'sternzeichen': 'Wassermann', 'text': 'Es wird besser', 

>  'headline': 'Horoskop f\xc3\xbcr Peter'}

>  

>  when I use

>  insert = "%headline, %text, %sternzeichen" %vars(articles)


Hi Charlie.  Let's take a look:


###
> >> articles = {'sternzeichen': 'Wassermann', 'text': 'Es wird besser',

...             'headline': 'Horoskop f\xc3\xbcr Peter'}
> >> vars(articles)

Traceback (most recent call last):
  File "<stdin> ", line 1, in ?

TypeError: vars() argument must have __dict__ attribute
> >> print vars.__doc__

vars([object]) ->  dictionary

 
Without arguments, equivalent to locals().
With an argument, equivalent to object.__dict__.
###


I see.  vars() is meant to grab all the variables out of something like a
module, but it appears that we can't do the same on a dictionary.  The
error message is somewhat confusing: the online docs should make it more
clear that not just any old object will do... hmmm.  I'll have to think
about a good reason why it behaves that way.


>  I get a TypeError:

>  TypeError: vars() argument must have __dict__ attribute

>  

>  but articles is a dictionary... what screamingly obvious thing am I

>  missing?



Start screaming.  *grin* We won't need to call vars() at all: we can just
do the interpolation directly with the dictionary that's in our hands:

###
> >> insert = "%(headline)s, %(text)s, %(sternzeichen)s" % articles

> >> print insert

Horoskop fr Peter, Es wird besser, Wassermann
###


Note: the string formatting above requires us to put the variables in the
'%(foo)s' sorta format --- the trailing 's' doesn't stand for plurality,
but for 'string'ality.

Hope this helps!


_______________________________________________
Tutor maillist  -  Tutor@[...].org
http://mail.python.org/mailman/listinfo/tutor