examples/hotplug.py

#!/usr/bin/env python
# Copyright (C) 2013-2021  Vincent Pelletier <plr.vincent@gmail.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

import usb1

def hotplug_callback(context, device, event):
    print("Device %s: %s" % (
        {
            usb1.HOTPLUG_EVENT_DEVICE_ARRIVED: 'arrived',
            usb1.HOTPLUG_EVENT_DEVICE_LEFT: 'left',
        }[event],
        device,
    ))
    # Note: cannot call synchronous API in this function.

def main():
    with usb1.USBContext() as context:
        if not context.hasCapability(usb1.CAP_HAS_HOTPLUG):
            print('Hotplug support is missing. Please update your libusb version.')
            return
        print('Registering hotplug callback...')
        opaque = context.hotplugRegisterCallback(hotplug_callback)
        print('Callback registered. Monitoring events, ^C to exit')
        try:
            while True:
                context.handleEvents()
        except (KeyboardInterrupt, SystemExit):
            print('Exiting')

if __name__ == '__main__':
    main()