Message 386020 - Python tracker

@Serhiy - Yes, I noted that problem in the PR. Thanks for pointing me to that issue, I agree it would be good to make pprint properly extensible (my current solution is to maintain a fork of the pprint module with dataclass support added).

Eric's suggestion would work, I wasn't sure if it would be considered an 'ok' thing to do, but if so then could be an easy enough way to support dataclasses (and namedtuples potentially)?