joining strings question

[Steve Holden]

patrick.waldo at gmail.com wrote:
> Hi all,
> 
> 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...
> 
> I've racked my brain for a while about this and I can't seem to figure
> it out.  Any ideas would be much appreciated.
> 
> Thanks

data = ['RULES', 'title','subtitle','pdf',
'title1','subtitle1','pdf1','NOTICES','title2','subtitle2','pdf','title3','subtitle3','pdf']
olist = []
while data:
   if data[0] == data[0].upper():
     olist.append([data[0]])
     del data[0]
   else:
     olist[-1].append(data[0]+' '+data[1])
     olist[-1].append(data[2])
     del data[:3]
print olist


However, I suspect you should be asking yourself whether this is really 
an appropriate data structure for your needs. If you say what you are 
trying to achieve in the large rather than focusing on a limited 
programming issue there may be much better solutions.

I suspect, for example, that a dict indexed by the categories and with 
the entries each containing a list of tuples might suit your needs much 
better, i.e.

{
   'RULES':   [('title subtitle', 'pdf'),
               ('title1 subtitle1', 'pdf')],
   'NOTICES': [('title2 subtitle2', 'pdf'),
                'title3 subtitle3', 'pdf')]}

One final observation: if all the files are PDFs then you might just as 
well throw the 'pdf' strings away and use a constant extension when you 
try and open them or whatever :-). Then the lists of tuples i the dict 
example could just become lists of strings.

regards
  Steve

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