Re: [Pyparsing] Naming elements based on their predecessor

[Joshua J. K. <jk...@sk...>]

On Thu, 2008-03-06 at 19:19 -0600, Paul McGuire wrote:
> >>>>
> Noticed something interesting: on a parsing object, an unknown attribute
> (such as 'asdfasdfsadf') will return '' (an empty string).  Is this intended
> behavior?  It makes testing for attributes via hasattr impossible.  I can
> always test for an empty string, of course, but I'd rather use exceptions
> and catch an AttributeError than an if/then block to see if the string is
> non-emtpy.
> >>>>
> 
> To test for the existence of an attribute:
> - if 'alsfjlsjafs' in results:
> - if results.alkjasdlfjslf == '':
>   or if results.laksjdfljsd:  # evaluating to '' is a boolean false value
> - results["sldflsjf"] will raise an exception if no such attribute

Right, I figured that out (testing on the empty value anyway), but it
surprised me that an invalid attribute didn't raise an exception.

Thanks again for all your help.

j

-- 
Joshua Kugler
VOC/SigNet Provider (aka Web App Programmer)
S&K Aerospace Alaska