On Sun, Dec 08, 2013 at 01:30:56PM +0200, Serhiy Storchaka wrote:
08.12.13 11:25, Steven D'Aprano написав(ла):
In the second case, there is a question about what to do with sequences that are not a multiple of the window size. Similar to zip(), there are two things one might do:
- pad with some given object; - raise an exception
3) emit last chunk incompleted;
Given a window size of two, and input data [a, b, c], are you suggesting a variety that returns this? (a,b), (c,) There is no need for a separate function for that. Given a version that takes a pad object, if the pad argument is not given, return a partial chunk at the end.
4) skip incomplete chunk.
The very next sentence in my post references that: "If you want to just ignore extra items, just catch the exception and continue." There is no need for an extra function covering that case.
There is also a question about result's type. Sometimes you need an iterator of subsequences (i.e. split string on equal string chunks), sometimes an iterator of iterators is enough.
None of the other itertools functions treat strings specially. Why should this one? If you want to re-join them into strings, you can do so with a trivial wrapper: (''.join(elements) for elements in group("some string", 3, pad=' ')) ought to do the trick, assuming group returns tuples or lists of characters. Re-combining the iterated-upon elements into the input type is not the responsibility of itertools. -- Steven