Python script to control the mediakeys on OS X. Used to emulate the mediakey on a keyboard with no such keys. Easiest used in combination with a launcher/trigger software such as Quicksilver.

mediakeys.py

#!/usr/bin/python

# CLI program to control the mediakeys on OS X. Used to emulate the mediakey on a keyboard with no such keys.
# Easiest used in combination with a launcher/trigger software such as Quicksilver.
# Main part taken from http://stackoverflow.com/questions/11045814/emulate-media-key-press-on-mac
# Glue to make it into cli program by Fredrik Wallner http://www.wallner.nu/fredrik/

import Quartz
import sys

# NSEvent.h
NSSystemDefined = 14

# hidsystem/ev_keymap.h
NX_KEYTYPE_SOUND_UP = 0
NX_KEYTYPE_SOUND_DOWN = 1
NX_KEYTYPE_PLAY = 16
NX_KEYTYPE_NEXT = 17
NX_KEYTYPE_PREVIOUS = 18
NX_KEYTYPE_FAST = 19
NX_KEYTYPE_REWIND = 20

supportedcmds = {'playpause': NX_KEYTYPE_PLAY, 'next': NX_KEYTYPE_NEXT, 'prev': NX_KEYTYPE_PREVIOUS, 'volup': NX_KEYTYPE_SOUND_UP, 'voldown': NX_KEYTYPE_SOUND_DOWN}

def HIDPostAuxKey(key):
	def doKey(down):
		ev = Quartz.NSEvent.otherEventWithType_location_modifierFlags_timestamp_windowNumber_context_subtype_data1_data2_(
			NSSystemDefined, # type
			(0,0), # location
			0xa00 if down else 0xb00, # flags
			0, # timestamp
			0, # window
			0, # ctx
			8, # subtype
			(key << 16) | ((0xa if down else 0xb) << 8), # data1
			-1 # data2
			)
		cev = ev.CGEvent()
		Quartz.CGEventPost(0, cev)
	doKey(True)
	doKey(False)

if __name__ == "__main__":
	try:
		command = sys.argv[1]
		assert(command in supportedcmds)
		HIDPostAuxKey(supportedcmds[command])
	except (IndexError, AssertionError):
		print "Usage: %s command" % (sys.argv[0],)
		print "\tSupported commands are %s" % supportedcmds.keys()

Hello there, I working on Mac OS Catalina 10.15.7, when I installed Quartz I got warning:

Cannot find reference 'CGEventPost' in '__init__.py | __init__.py'

How to solve them?

As I said above, this script is really dated so I don't remember and I don't use it any longer either. So I'm afraid I cannot help much. Did you really get the error when you installed Quartz?

I already installed quartz.However your code is working, despite the error.

And I want to ask you, where did you find Quartz documentation? I have seen the official Quartz documentation but have not found an explanation for it methods this framework.

I just copied the main thing from the StackOverflow answer that is linked in the top comment of the script. My only contribution was adding the CLI.

I've updated the script for python 3 and worked out the correct egg to install:
https://gist.github.com/aleksandersumowski/a296a910fd3c6722744a2c3b0a1b5bf5

the script assumes python 3 installed via homebrew on a M* computer