CLN: assorted cleanups, mostly post-black fixups
Mostly fixing extra " " introduced by black (will take a look at the issue tracker there to see if that can be fixed once and for all).

Also change `except Foo as e:` to `except Foo as err` and remove one `except Exception` in a docs file.  Clarified a whatsnew note that @jorisvandenbossche asked for a while back.
Hello @jbrockmendel! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:























































There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2019-10-10 13:43:23 UTC Opened an issue with black: https://github.com/psf/black/issues/1051 Thanks!