This is not supported. Just to give you the historical background: we started with a C++ core framework. In there, all one can access, from within a vision module, all core functionality (like list the mappings, etc) by calling the appropriate functions on the JeVois Engine object (which is always at the root of a vision pipeline). Then we added the command-line interface as a way for the host computer to also access some of the core functions, over a serial port. Finally we added python support on top of the C++ core, with some direct bindings from the core to the Python side of things, shown here:
(see section on Python bindings provided by jevois core).
Now we did not provide a python binding for something like listmappings because a vision module (the python code you are writing) should not need to know that. It should work just for whatever mappings it can support, and the host computer is in charge of picking a mapping (and hence a vision module) it wants to run. If listmappings is indeed what you want, then can you tell us why you would need it? From within a vision module, you should never have to worry about that list. If you want something else, maybe we can add a python binding for that?
In the meantime, the best way to quickly solve your problem is to have your host computer issue some commands to the jevois command-line interface, for example like here:
if you scroll down to the first piece of source code, line 43 the Arduino sends this to the JeVois camera:
SERIAL.println("setpar serlog None");
to configure it.
Or in this one:
some python program running on the host sends some commands to JeVois as the sliders in the Python GUI are moved around.