coolio

gistfile1.txt

import os
from os.path import join

"""find_tty_usb('067b', '2302') -> '/dev/ttyUSB0'"""
# Note: if searching for a lot of pairs, it would be much faster to search
# for the enitre lot at once instead of going over all the usb devices
# each time.
for dnbase in os.listdir('/sys/bus/usb/devices'):
    dn = join('/sys/bus/usb/devices', dnbase)
    if not os.path.exists(join(dn, 'idVendor')):
        continue
    idv = open(join(dn, 'idVendor')).read().strip()
    # if idv != idVendor:
    #    continue
    idp = open(join(dn, 'idProduct')).read().strip()
    #if idp != idProduct:
    #    continue
    print(idv, idp)
    
    for subdir in os.listdir(dn):
        if subdir.startswith(dnbase+':'):
            for subsubdir in os.listdir(join(dn, subdir)):
    #            print('--->', subsubdir)
                if subsubdir.startswith('ttyUSB'):
                   print('-->', subsubdir);
                if subsubdir.startswith('tty'):
                   print('-->', subsubdir);
    #                return join('/dev', subsubdir)