I can think of a quick code like this.

Since all USB ports can be accessed via /dev/bus/usb/< bus >/< device >

For the ID generated, even if you unplug the device and reattach it [ could be some other port ]. It will be the same.

import re
import subprocess
device_re = re.compile("Bus\s+(?P<bus>\d+)\s+Device\s+(?P<device>\d+).+ID\s(?P<id>\w+:\w+)\s(?P<tag>.+)$", re.I)
df = subprocess.check_output("lsusb")
devices = []
for i in df.split('\n'):
    if i:
        info = device_re.match(i)
        if info:
            dinfo = info.groupdict()
            dinfo['device'] = '/dev/bus/usb/%s/%s' % (dinfo.pop('bus'), dinfo.pop('device'))
            devices.append(dinfo)
print devices

Sample output here will be:

[
{'device': '/dev/bus/usb/001/009', 'tag': 'Apple, Inc. Optical USB Mouse [Mitsumi]', 'id': '05ac:0304'},
{'device': '/dev/bus/usb/001/001', 'tag': 'Linux Foundation 2.0 root hub', 'id': '1d6b:0002'},
{'device': '/dev/bus/usb/001/002', 'tag': 'Intel Corp. Integrated Rate Matching Hub', 'id': '8087:0020'},
{'device': '/dev/bus/usb/001/004', 'tag': 'Microdia ', 'id': '0c45:641d'}
]

Code Updated for Python 3

import re
import subprocess
device_re = re.compile(b"Bus\s+(?P<bus>\d+)\s+Device\s+(?P<device>\d+).+ID\s(?P<id>\w+:\w+)\s(?P<tag>.+)$", re.I)
df = subprocess.check_output("lsusb")
devices = []
for i in df.split(b'\n'):
    if i:
        info = device_re.match(i)
        if info:
            dinfo = info.groupdict()
            dinfo['device'] = '/dev/bus/usb/%s/%s' % (dinfo.pop('bus'), dinfo.pop('device'))
            devices.append(dinfo)
            
print(devices)