Python usb detection

Question

First sorry for my english !

my environement :
python : 2.7.3
wxwidgets : 2.9.4-1
wxpython : 2.9.4-1
ubuntu : 12.04

context :
I have to detect when an usb hard-drive is plugged or unplugged and do some action on it.
For example when a disk is plugged i wan to get the mount point (ex:/media/usb0) and the system point (ex:/dev/sdb1). I need both two path and i do not want made a system call like (subprocess : mount -l).

I have tried several ways :
- pyudev : only get the system path on EVT_DEVICE_ADDED (like /dev/sdb1)
- Gio (gi.repository) : get the mount point with 'mount-added' (like /media/usb0) and the system point in an second event 'volume-added' but i have problems with Gio add and remove event fail or have suspect behavior depends on computer i have tried my application on it
- DBusGMainLoop (dbus.mainloop.glib) : Works but depends on computer i tried it (all on the same configuration) launch 2 event 'DeviceAdded', and sometime one DeviceChanged but sometime not when a disk is plugged.

Do you know a way (maybe one of the 3 i exposed, i have done something bad) to detect when an usb disk is plugged, call a method and in this method get the 2 path i need ?

Thanks in advance.

Aurélien.

Answer 1

I use this to check attached USB devices:

Requirements

• pyusb

Example

import usb
from usb.core import USBError

### Some auxiliary functions ###
def _clean_str(s):
    '''
    Filter string to allow only alphanumeric chars and spaces

    @param s: string
    @return: string
    '''

    return ''.join([c for c in s if c.isalnum() or c in {' '}])


def _get_dev_string_info(device):
    '''
    Human readable device's info

    @return: string
    '''

    try:
        str_info = _clean_str(usb.util.get_string(device, 256, 2))
        str_info += ' ' + _clean_str(usb.util.get_string(device, 256, 3))
        return str_info
    except USBError:
        return str_info


def get_usb_devices():
    '''
    Get USB devices

    @return: list of tuples (dev_idVendor, dev_idProduct, dev_name)
    '''

    return [(device.idVendor, device.idProduct, _get_dev_string_info(device)) 
                for device in usb.core.find(find_all=True)
                    if device.idProduct > 2]

I hope it helps! I have some more code related to USB stuff here