How to tell if server running from API

Tim <[email protected]> Sat, 30 Mar 2019 21:01:59 -0400

Newsgroups	gmane.comp.audio.jackit
Message-ID	<[email protected]>

This may have been answered recently but I can't find it.
Is there a way, via the Jack API or Jack server API,
  to ask if Jack is already running?

I see there is a DBus command for that in jack_control,
  but jack_control crashes for me. Maybe my Python's fault?

Thanks.
Tim.