Returns the full path to a Gtk icon file by icon name

gtk-icon-path

#!/usr/bin/env python3
import os, sys

import gi
gi.require_version('Gtk', '3.0')

from gi.repository import Gtk

if len(sys.argv) < 2:
    sys.stderr.write("Usage:\n")
    sys.stderr.write("    {} ICON_NAME [ICON_SIZE]\n".format(os.path.basename(__file__)))
    sys.exit(1)

icon_name = sys.argv[1]
icon_size = int(sys.argv[2]) if len(sys.argv) >= 3 else 64

icon_theme = Gtk.IconTheme.get_default()
icon_info = icon_theme.lookup_icon(icon_name, icon_size, 0)

if not icon_info:
    sys.stderr.write("Unknown icon: {}\n".format(sys.argv[1]))
    sys.exit(1)

print(icon_info.get_filename())