(PyUSB) detect the last/new plug USB

Question

I have a function can list out all the computer connection with USB port.

I want to detect the last/new USB I just plug in, then print out it's txt file from last/new USB I just plug.

One way I come up is that the function can run time1, before I plug USB in. Then there are 10 devices. After I plug in, time2, there are 11 devices. So I can differentiate the last one.

I read through relate question, Trigger new plugged USB-HDD or USB-Stick device but still not sure how to do.

function can list out all the computer connection with USB port:

import usb.core
import usb.backend.libusb1

print('idVendor  idProduct  Manufacturer - Product')
print('----------------------------------------------------')



busses = usb.busses()
for bus in busses:
    for dev in bus.devices:
        if dev:
            xdev = usb.core.find(idVendor=dev.idVendor, idProduct=dev.idProduct)
            if xdev._manufacturer is None:
                xdev._manufacturer = usb.util.get_string(xdev, xdev.iManufacturer)
            if xdev._product is None:
                xdev._product = usb.util.get_string(xdev, xdev.iProduct)
            print('%8d  %9d  %s - %s' % (dev.idVendor, dev.idProduct,
                                         str(xdev._manufacturer).strip(),
                                         str(xdev._product).strip()))

output of all USB:

idVendor      idProduct      Manufacturer     - Product
----------------------------------------------------
    1133      49271  Logitech - USB Optical Mouse
    1423      37728   - USB Reader    34148       4096  JetFlash - Mass Storage Device
    7531          2  Linux 5.15.0-48-generic xhci-hcd - xHCI Host Controller
    7531          3  Linux 5.15.0-48-generic xhci-hcd - xHCI Host Controller
    5117       2112  Generic - External
    7531          2  Linux 5.15.0-48-generic xhci-hcd - xHCI Host Controller
    7531          3  Linux 5.15.0-48-generic xhci-hcd - xHCI Host Controller

Where does the source come from? [Found it very similar here](https://stackoverflow.com/questions/8110310/simple-way-to-query-connected-usb-devices-info-in-python). — hc_dev, Oct 03 '22 at 17:37

score 2 · Accepted Answer · answered Oct 03 '22 at 18:40

You can use a dictionary to keep track of found devices. Each device has its unique serial-id which can be used as key.

Then repeat the scan several times (e.g. in a loop with some seconds delay). If a device is not yet registered in the dictionary with its serial-id, you know it was recently added.

Example

import time
from usb.core import find
from usb.util import get_string
import usb.backend.libusb1


def info_usb_device(dev):
    xdev = find(idVendor=dev.idVendor, idProduct=dev.idProduct)
    if xdev.bDeviceClass == 9:  # don't list HUBs, see [USB class-codes](https://www.usb.org/defined-class-codes)
        return
    if xdev._manufacturer is None:
        xdev._manufacturer = get_string(xdev, xdev.iManufacturer, langid=1033)
    if xdev._product is None:
        xdev._product = get_string(xdev, xdev.iProduct, langid=1033)
    device_info = '[%20s] %8d %9d %s - %s' % (xdev.serial_number, dev.idVendor, dev.idProduct,
                                 str(xdev._manufacturer).strip(),
                                 str(xdev._product).strip())
    return (xdev.serial_number, device_info)


def add_usb_devices(device_dict):
    new_devices = []
    for bus in usb.busses():
        for dev in bus.devices:
            if dev is None:
                continue
            serial_info = info_usb_device(dev)
            if serial_info is not None:
                (serial, info) = serial_info
                if serial not in device_dict:
                    new_devices.append(serial)
                    device_dict[serial] = info
    return new_devices


if __name__ == "__main__":
    device_dict = {}
    print('%22s %8s %9s %s' % ('serial', 'idVendor', 'idProduct', 'Manufacturer - Product'))
    print('-'*22, '-'*8,  '-'*9, '-'*30)
    # first scan
    add_usb_devices(device_dict)
    for device_info in device_dict.values():
        print(device_info)
    # next scans
    for i in range(5):  # run 5 more scans 
        new_serials = add_usb_devices(device_dict)
        if len(new_serials) > 0:
           print('** (scan %d) FOUND NEW USB DEVICES/SERIALS: %s' % (i, new_serials))
           for serial in new_serials:
               print(device_dict[serial])
        time.sleep(3)  # waiting 3 seconds before new scan
    print('Scans completed.')

that amazing, and can I combine def `add_usb_devices(device_dict)` and `info_usb_device(dev)` to one funtion? — , Oct 05 '22 at 09:42
@俠客行, we made your code working. To get answers on how to combine them, I would suggest to raise this question concerning _refactoring_ at the sister-site [codereview.se]. The community there can help you to improve your code. — hc_dev, Oct 05 '22 at 18:54

(PyUSB) detect the last/new plug USB

1 Answers1

Example

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