Code Explaination: Spelling correction code

[Steven Bethard]

Drew wrote:
> I recently saw this website: http://www.norvig.com/spell-correct.html
> 
> All the code makes sense to me save one line:
> 
> def known_edits2(word):
>     return set(e2 for e1 in edits1(word) for e2 in edits1(e1) if e2 in
> NWORDS)

This is the same as:

     result = set()
     for e1 in edits1(word):
         for e2 in edits1(e1):
             if e2 in NWORDS:
                 result.add(e2)
     return result

The thing between the ``set(`` and ``)`` is called a generator 
comprehension if you'd like to look into it further.

STeVe