[python/en] Fix 80 col limit and clarify a few points.

I noticed a few missing features, some potentially misleading information, and some lines that were longer than 80 characters. This patch is my suggestion for fixes to these, although I'm happy to update anything which seems incorrect.

I'll add some comments to the diff.
Perhaps reiterate the conflation of terms in another comment somewhere that indicates you can expand any tuples or dictionaries using the * and ** operators, in any context.