This script mutes Spotify when it plays advertisements.

spotisilencer.py

#!/usr/bin/env python3
# encoding: utf-8

import sys
import dbus
import dbus.mainloop.glib
import subprocess
import time
import re
from gi.repository import GLib
import pulsectl # https://github.com/mk-fg/python-pulse-control

def pulse_mute_spotify(mutestate):
    with pulsectl.Pulse('spotisilencer') as pulse:
        for sink_input in pulse.sink_input_list():
            # sink_input.name in ['Spotify', 'Playback'] is ambiguous
            binary = sink_input.proplist.get('application.process.binary', None)
            if (binary == 'spotify'):
                pulse.sink_input_mute(sink_input.index, mutestate)
                print(f'Set mutestate to {mutestate} for sink ({sink_input}) of {binary}.')

def is_advert(metadata):
    """ Whether the current song is an advertisement. """
    if 'Metadata' in metadata:
        m = metadata['Metadata']
        artist = m['xesam:artist'][0]
        return artist == ""
    else:
        return False

def propertiesChanged_handler(sender=None, metadata=None, sig=None):
    time.sleep(0.5) # event comes a bit earlier than actual content change
    is_ad = is_advert(metadata)
    pulse_mute_spotify(is_ad)

def main():
    dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
    bus = dbus.SessionBus()
    try:
        remote_object = bus.get_object(
            "org.mpris.MediaPlayer2.spotify",
            "/org/mpris/MediaPlayer2"
        )
        change_manager = dbus.Interface(
            remote_object,
            'org.freedesktop.DBus.Properties'
        )
        change_manager.connect_to_signal(
            "PropertiesChanged",
            propertiesChanged_handler
        )
    except dbus.exceptions.DBusException as dbe:
        if (dbe.get_dbus_name() == "org.freedesktop.DBus.Error.ServiceUnknown"):
            print(f"Please start Spotify first. ({dbe.get_dbus_message()})")
            sys.exit(1)
    loop = GLib.MainLoop()
    loop.run()

if __name__ == '__main__':
    main()