Decode QR Codes in Python with Zxing: A Complete Step-by-Step Tutorial

Zxing for QR Code Recognition

The author initially tried ZBar but encountered 32‑bit DLL errors on a 64‑bit system and learned that ZBar cannot handle tilted or locate barcodes. Consequently, Zxing was chosen as an alternative.

Installation

Install the Python wrapper for Zxing via pip:

pip install zxing

Complete Python Script

The following script demonstrates how to decode a single‑image QR code using Zxing. It creates a temporary JPEG file, decodes the barcode, logs the outcome, and removes the temporary file.

#encoding:utf8
"""
Single‑image QR code must be processed individually; multiple images may cause issues.
This example supports only JPG format.
"""
import os
import logging
from PIL import Image
import zxing
import random

logger = logging.getLogger(__name__)
if not logger.handlers:
    logging.basicConfig(level=logging.INFO)
DEBUG = (logging.getLevelName(logger.getEffectiveLevel()) == 'DEBUG')

def ocr_qrcode_zxing(filename):
    # Generate a temporary file in the current directory
    img = Image.open(filename)
    ran = int(random.random() * 100000)
    temp_name = f"{os.path.basename(filename).split('.')[0]}{ran}.jpg"
    img.save(temp_name)
    zx = zxing.BarCodeReader()
    data = ''
    zxdata = zx.decode(temp_name)
    # Delete the temporary file
    os.remove(temp_name)
    if zxdata:
        logger.debug(f"zxing recognized QR code: {filename}, content: {zxdata}")
        data = zxdata
    else:
        logger.error(f"Error recognizing QR code with zxing: {filename}")
        img.save(f"{filename}-zxing.jpg")
    return data

if __name__ == '__main__':
    # Path to the QR code image
    filename = r'/Users/xxx/Downloads//3333.jpg'
    # Perform QR code recognition using Zxing
    ltext = ocr_qrcode_zxing(filename)
    logger.info(f"[{filename}] Zxing QR code result: [{ltext}]!!!")
    print(ltext)

The script logs detailed debug information when the logging level is set to DEBUG, and it provides error handling by saving a copy of the problematic image.

Note: The article originally included a promotional QR code image for additional resources, which has been removed as it does not pertain to the technical content.