Python Script to Use the Computer Camera to Scan Barcodes

I was going to buy a Honeywell MS7120 but ended up writing this Python code to use the camera on my Surface as a UPC barcode scanner for when I'm listing and don't want to transpose numbers. It will copy the barcode into your clipboard to be pasted into eBay. Hope it helps someone else, too:

import cv2
from pyzbar import pyzbar
import sys
import pyperclip
import time

def set_focus(camera, value):
    camera.set(cv2.CAP_PROP_AUTOFOCUS, 0)
    camera.set(cv2.CAP_PROP_FOCUS, value)

def scan_barcode():
    # Change the camera index to use the front or rear-facing camera
    camera_index = 0
    cap = cv2.VideoCapture(camera_index)

    # Set an initial focus value
    focus_value = 0.0
    set_focus(cap, focus_value)

    last_focus_change_time = time.time()

    while True:
        ret, frame = cap.read()
        barcodes = pyzbar.decode(frame)
        
        for barcode in barcodes:
            (x, y, w, h) = barcode.rect
            cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 0, 255), 2)
            barcode_data = barcode.data.decode('utf-8')
            barcode_type = barcode.type
            text = f"{barcode_data} ({barcode_type})"
            cv2.putText(frame, text, (x, y - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2)
            
            # Copy the barcode data to the clipboard
            pyperclip.copy(barcode_data)
            print(f"Barcode data: {barcode_data}, type: {barcode_type}")
            sys.exit(0)

        cv2.imshow('Barcode Scanner', frame)
        key = cv2.waitKey(1) & 0xFF

        if key == ord('q'):
            break

        # Check if it's time to change the focus
        if time.time() - last_focus_change_time > 3:
            focus_value = (focus_value + 0.5) % 1.0
            set_focus(cap, focus_value)
            last_focus_change_time = time.time()

    cap.release()
    cv2.destroyAllWindows()

if __name__ == "__main__":
    scan_barcode()