joining strings question

[Tim Chase]

> I have some data with some categories, titles, subtitles, and a link
> to their pdf and I need to join the title and the subtitle for every
> file and divide them into their separate groups.
> 
> So the data comes in like this:
> 
> data = ['RULES', 'title','subtitle','pdf',
> 'title1','subtitle1','pdf1','NOTICES','title2','subtitle2','pdf','title3','subtitle3','pdf']
>
> What I'd like to see is this:
> 
> [RULES', 'title subtitle','pdf', 'title1 subtitle1','pdf1'],
> ['NOTICES','title2 subtitle2','pdf','title3 subtitle3','pdf'], etc...

The following iterator yields things that look like each of those 
items:

   def category_iterator(source):
     source = iter(source)
     last_cat = None
     entries = []
     try:
       while True:
         item = source.next()
         if item == item.upper(): # categories are uppercase
           if last_cat:
             yield [last_cat] + entries
           last_cat = item
           entries = []
         else:
           title = item
           subtitle = source.next()
           link = source.next()
           entries.append('%s %s' % (title, subtitle))
           entries.append(link)
     except StopIteration:
       if last_cat:
         yield [last_cat] + entries

   if __name__ == '__main__':
     data = ['RULES',
             'title','subtitle','pdf',
             'title1','subtitle1','pdf1',
             'NOTICES',
             'title2','subtitle2','pdf',
             'title3','subtitle3','pdf']
     for compact_category_info in category_iterator(data):
       print repr(compact_category_info)

If your input data is malformed, you may get peculiar results 
depending on how pathologically malformed that data is.

Hope this helps,

-tkc