RtMidi is a set of C++ classes which provides a concise and simple,
cross-platform API (Application Programming Interface) for realtime MIDI
input / output across Linux (ALSA & JACK), macOS / OS X (CoreMIDI & JACK),
and Windows (MultiMedia System) operating systems.
python-rtmidi is a Python binding for RtMidi implemented using Cython and
provides a thin wrapper around the RtMidi C++ interface. The API is basically
the same as the C++ one but with the naming scheme of classes, methods and
parameters adapted to the Python PEP-8 conventions and requirements of the
Python package naming structure. python-rtmidi supports Python 2 (tested
with Python 2.7) and Python 3 (3.4, 3.5, 3.6 and 3.7).
Here’s a quick example of how to use python-rtmidi to open the first
available MIDI output port and send a middle C note on MIDI channel 1: