What I have is a bunch of PDFs (few 100s). They don't have a proper structure nor do they have particular fields. All they have is lot of text. 
What I am trying to do : 
Index the PDFs and search for some keywords against the index. 
I am interested in finding if that particular keyword is in the PDF doc and if it is, I want the line where the keyword is found. 
If I searched for 'Google' in a PDF doc that has that term, I would like to see 'Google is a great search engine' which is the line in the PDF. 
How I decided to do :
Either use SOLR or Whoosh but SOLR is looking good for inbuilt PDF support. I prefer to code in Python and Sunburst is a wrapper on SOLR which I like. 
SOLR's sample/example project has some price comparision based schema file. Now I am not sure if I can use SOLR to answer my problem.
What do you guys suggest? Any input is much appreciated.
I once solved this by converting the PDF files to text with utilities as pdftotext (pdftohtml would also work I guess), generating a 'cache' of some sorts. Then using some grep I searched the text file cache for keywords.
This is slightly different from your proposed solution, but I can imagine you can call this from Python as well.
How do I Index PDF files and search for keywords?