Terry Reedy, 30.06.2012 23:09:
For the doc, I think it would be helpful here and in most module subchapters if there were a subchapter table of contents at the top (under 9.1 in this case). Even though just 2 lines here (currently, but see below), it would let people know that there *is* a recipes section. After the appropriate tables, mention that there are example uses in the recipe section. Possibly add similar tables in the recipe section.
+1, the recipes are interesting enough to be highly visible, both as usage examples and to solve actual problems.
Another addition could be a new subsection on grouping (chunking) that would discuss post-processing of grouper (as discussed above), as well as other recipes, including ones specific to strings and sequences. It would essentially be a short how-to. Call it 9.1.3 "Grouping, Blocking, or Chunking Sequences and Iterables". The synonyms will help external searching. A toc would let people who have found this doc know to look for this at the bottom.
If it really is such an important use case for so many people, I agree that it's worth special casing it in the docs. It's not a trivial algorithmic step from a sequential iterable to a grouped iterable.