How to Generate and Read QR Codes with Python

QR codes are machine‑readable two‑dimensional barcodes originally invented in 1994 by Denso Wave for tracking automotive parts and later popularized by smartphones for payments, menus, Wi‑Fi sharing, and more.

To generate QR codes in Python, first install the qrcode package:

pip install qrcode

A minimal example creates a QR code that encodes the text "Hello World":

import qrcode
img = qrcode.make('Hello World')
img.save('hello.png')

For more control, use the QRCode class with parameters such as version , error_correction , box_size , and border . The following code generates a red‑on‑black QR code linking to a Medium profile:

qr = qrcode.QRCode(
    version=1,
    error_correction=qrcode.constants.ERROR_CORRECT_L,
    box_size=10,
    border=4,
)
qr.add_data("https://abhijithchandradas.medium.com/")
qr.make(fit=True)
img = qr.make_image(fill_color="red", back_color="black")
img.save("medium.png")

To read QR codes, install OpenCV (the cv2 module) and use its QRCodeDetector :

pip install cv2
import cv2
img = cv2.imread("medium.png")
det = cv2.QRCodeDetector()
val, pts, st_code = det.detectAndDecode(img)
print(val)  # prints the decoded URL

The detectAndDecode function returns the decoded content, the corner points of the QR code, and a binarized image. This guide provides a complete workflow for creating and decoding QR codes in Python.

Original article: Create and Read QR Code Using Python