nixos-config/modules/workspace/i3blocks/scripts/music.nix

{ python3, playerctl, iconfont, ...}: ''
  #!${python3}/bin/python
  from subprocess import getoutput, call
  from os import environ
  status = getoutput("${playerctl}/bin/playerctl status")
  if "BLOCK_BUTTON" in environ:
    BLOCK_BUTTON = environ["BLOCK_BUTTON"]
    if BLOCK_BUTTON == "1": call(["${playerctl}/bin/playerctl", "play-pause"])
    if BLOCK_BUTTON == "2": call(["${playerctl}/bin/playerctl", "stop"])
    if BLOCK_BUTTON == "3": call(["${playerctl}/bin/playerctl", "next"])
  if status == "Paused" or status == "Playing":
    text = getoutput("${playerctl}/bin/playerctl metadata title")[:20:]
    icon = ""
  else:
    text = ""
    icon = ""
  print("<span font='${iconfont}'>%s</span> %s" % (icon, text.replace('&', '&amp;')))
''