Creating QR Code With Google

4/11/2013
2-minute read

So today I thought I would be neat to show how to quickly create QR codes using Google’s Chart Tools .

Google gives us a extremely easy way to create QR code by sending GET data request via URL: https://chart.googleapis.com/chart?cht=qr&chs=300x300&chl=nessy That is nice and easy, but I figured I would wrap this up in a small Python script just because:

#!/usr/bin/env python
from urllib2 import quote, urlopen, Request
from poster.encode import multipart_encode
from poster.streaminghttp import register_openers
import sys

def create(width, heigth, data):
    '''Builds a URL for Google to create us a QR code'''
    # build and make URL request
    google_chart = 'https://chart.googleapis.com'
    url = '%s/chart?cht=qr&chs=%sx%s&chl=%s' % (google_chart, width, heigth, quote(data))
    request = urlopen(url)
    response = request.read()

    # write QR code to file
    f = open('qr.png', 'w')
    f.write(response)
    f.close
    return 'Wrote qr.png..'

def read(qr_file):
    '''Reads a QR code by URL'''
    # post image to decode page
    register_openers()
    datagen, headers = multipart_encode({'f': open(qr_file)})
    request = Request('http://zxing.org/w/decode', datagen, headers)
    response = urlopen(request).read()
    return response

if sys.argv[1] == 'create':
    print create(300, 300, sys.argv[2])

if sys.argv[1] == 'read':
    print read(sys.argv[2])

Basic usage works like so:

$ ./qr.py create "My name is Nessy, Hello"
Wrote qr.png..

Running the create option will write a file named qr.png to your current directory:

$ file qr.png
qr.png: PNG image, 300 x 300, 8-bit/color RGB, non-interlaced

And reading this QR code works just like this:

$ ./qr.py read qr.png
My name is Nessy, Hello

Development Python