i3visio / python-qrcode

Python QR Code image generator

Pure python QR Code generator

This module uses image libraries, Python Imaging Library (PIL) by default, to generate QR Codes.

It is recommended to use the pillow fork rather than PIL itself.

What is a QR Code?

A Quick Response code is a two-dimensional pictographic code used for its fast readability and comparatively large storage capacity. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be made up of any kind of data (e.g., binary, alphanumeric, or Kanji symbols)

Usage

From the command line, use the installed qr script:

qr "Some text" > test.png

Or in Python, use the make shortcut function:

import qrcode
img = qrcode.make('Some data here')

Advanced Usage

For more control, use the QRCode class. For example:

import qrcode
qr = qrcode.QRCode(
    version=1,
    error_correction=qrcode.constants.ERROR_CORRECT_L,
    box_size=10,
    border=4,
)
qr.add_data('Some data')
qr.make(fit=True)

img = qr.make_image()

The version parameter is an integer from 1 to 40 that controls the size of the QR Code (the smallest, version 1, is a 21x21 matrix). Set to None and use the fit parameter when making the code to determine this automatically.

The error_correction parameter controls the error correction used for the QR Code. The following four constants are made available on the qrcode package:

ERROR_CORRECT_L

About 7% or less errors can be corrected.

ERROR_CORRECT_M (default)

About 15% or less errors can be corrected.

ERROR_CORRECT_Q

About 25% or less errors can be corrected.

ERROR_CORRECT_H.

About 30% or less errors can be corrected.

The box_size parameter controls how many pixels each "box" of the QR code is.

The border parameter controls how many boxes thick the border should be (the default is 4, which is the minimum according to the specs).

Other image factories

You can encode as SVG, or use a new pure Python image processor to encode to PNG images.

The Python examples below use the make shortcut. The same image_factory keyword argument is a valid option for the QRCode class for more advanced usage.

SVG

On Python 2.6 must install lxml since the older xml.etree.ElementTree version can not be used to create SVG images.

You can create the entire SVG or an SVG fragment. When building an entire SVG image, you can use the factory that combines as a path (recommended, and default for the script) or a factory that creates a simple set of rectangles.

From your command line:

qr --factory=svg-path "Some text" > test.svg
qr --factory=svg "Some text" > test.svg
qr --factory=svg-fragment "Some text" > test.svg

Or in Python:

import qrcode
import qrcode.image.svg

if method == 'basic':
    # Simple factory, just a set of rects.
    factory = qrcode.image.svg.SvgImage
elif method == 'fragment':
    # Fragment factory (also just a set of rects)
    factory = qrcode.image.svg.SvgFragmentImage
else:
    # Combined path factory, fixes white space that may occur when zooming
    factory = qrcode.image.svg.SvgPathImage

img = qrcode.make('Some data here', image_factory=factory)

Two other related factories are available that work the same, but also fill the background of the SVG with white:

qrcode.image.svg.SvgFillImage
qrcode.image.svg.SvgPathFillImage

Pure Python PNG

Install the following two packages:

pip install git+git://github.com/ojii/pymaging.git#egg=pymaging
pip install git+git://github.com/ojii/pymaging-png.git#egg=pymaging-png

From your command line:

qr --factory=pymaging "Some text" > test.png

Or in Python:

import qrcode
from qrcode.image.pure import PymagingImage
img = qrcode.make('Some data here', image_factory=PymagingImage)