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=============================
Pure python QR Code generator
=============================
Generate QR codes.
For a standard install (which will include pillow_ for generating images),
run::
pip install qrcode[pil]
.. _pillow: https://pypi.python.org/pypi/Pillow
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:
.. code:: python
import qrcode
img = qrcode.make('Some data here')
Advanced Usage
--------------
For more control, use the ``QRCode`` class. For example:
.. code:: python
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(fill_color="black", back_color="white")
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.
``fill_color`` and ``back_color`` can change the background and the painting
color of the QR, when using the default image factory.
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
---
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:
.. code:: 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:
.. code:: python
import qrcode
from qrcode.image.pure import PymagingImage
img = qrcode.make('Some data here', image_factory=PymagingImage)
==========
Change log
==========
6.0 (23 March 2018)
===================
- Fix optimize length being ignored in ``QRCode.add_data``.
- Better calculation of the best mask pattern and related optimizations. Big
thanks to cryptogun!
5.3 (18 May 2016)
=================
* Fix incomplete block table for QR version 15. Thanks Rodrigo Queiro for the
report and Jacob Welsh for the investigation and fix.
* Avoid unnecessary dependency for non MS platforms, thanks to Noah Vesely.
* Make ``BaseImage.get_image()`` actually work.
5.2 (25 Jan 2016)
=================
* Add ``--error-correction`` option to qr script.
* Fix script piping to stdout in Python 3 and reading non-UTF-8 characters in
Python 3.
* Fix script piping in Windows.
* Add some useful behind-the-curtain methods for tinkerers.
* Fix terminal output when using Python 2.6
* Fix terminal output to display correctly on MS command line.
5.2.1
-----
* Small fix to terminal output in Python 3 (and fix tests)
5.2.2
-----
* Revert some terminal changes from 5.2 that broke Python 3's real life tty
code generation and introduce a better way from Jacob Welsh.
5.1 (22 Oct 2014)
=================
* Make ``qr`` script work in Windows. Thanks Ionel Cristian Mărieș
* Fixed print_ascii function in Python 3.
* Out-of-bounds code version numbers are handled more consistently with a
ValueError.
* Much better test coverage (now only officially supporting Python 2.6+)
5.0 (17 Jun 2014)
=================
* Speed optimizations.
* Change the output when using the ``qr`` script to use ASCII rather than
just colors, better using the terminal real estate.
* Fix a bug in passing bytecode data directly when in Python 3.
* Substation speed optimizations to best-fit algorithm (thanks Jacob Welsh!).
* Introduce a ``print_ascii`` method and use it as the default for the ``qr``
script rather than ``print_tty``.
5.0.1
-----
* Update version numbers correctly.
4.0 (4 Sep 2013)
================
* Made qrcode work on Python 2.4 - Thanks tcely.
Note: officially, qrcode only supports 2.5+.
* Support pure-python PNG generation (via pymaging) for Python 2.6+ -- thanks
Adam Wisniewski!
* SVG image generation now supports alternate sizing (the default box size of
10 == 1mm per rectangle).
* SVG path image generation allows cleaner SVG output by combining all QR rects
into a single path. Thank you, Viktor Stískala.
* Added some extra simple SVG factories that fill the background white.
4.0.1
-----
* Fix the pymaging backend not able to save the image to a buffer. Thanks ilj!
4.0.2
-----
* Fix incorrect regex causing a comma to be considered part of the alphanumeric
set.
* Switch to using setuptools for setup.py.
4.0.3
-----
* Fix bad QR code generation due to the regex comma fix in version 4.0.2.
4.0.4
-----
* Bad version number for previous hotfix release.
3.1 (12 Aug 2013)
=================
* Important fixes for incorrect matches of the alpha-numeric encoding mode.
Previously, the pattern would match if a single line was alpha-numeric only
(even if others wern't). Also, the two characters ``{`` and ``}`` had snuck
in as valid characters. Thanks to Eran Tromer for the report and fix.
* Optimized chunking -- if the parts of the data stream can be encoded more
efficiently, the data will be split into chunks of the most efficient modes.
3.1.1
-----
* Update change log to contain version 3.1 changes. :P
* Give the ``qr`` script an ``--optimize`` argument to control the chunk
optimization setting.
3.0 (25 Jun 2013)
=================
* Python 3 support.
* Add QRCode.get_matrix, an easy way to get the matrix array of a QR code
including the border. Thanks Hugh Rawlinson.
* Add in a workaround so that Python 2.6 users can use SVG generation (they
must install ``lxml``).
* Some initial tests! And tox support (``pip install tox``) for testing across
Python platforms.
2.7 (5 Mar 2013)
================
* Fix incorrect termination padding.
2.6 (2 Apr 2013)
================
* Fix the first four columns incorrectly shifted by one. Thanks to Josep
Gómez-Suay for the report and fix.
* Fix strings within 4 bits of the QR version limit being incorrectly
terminated. Thanks to zhjie231 for the report.
2.5 (12 Mar 2013)
=================
* The PilImage wrapper is more transparent - you can use any methods or
attributes available to the underlying PIL Image instance.
* Fixed the first column of the QR Code coming up empty! Thanks to BecoKo.
2.5.1
-----
* Fix installation error on Windows.
2.4 (23 Apr 2012)
=================
* Use a pluggable backend system for generating images, thanks to Branko Čibej!
Comes with PIL and SVG backends built in.
2.4.1
-----
* Fix a packaging issue
2.4.2
-----
* Added a ``show`` method to the PIL image wrapper so the ``run_example``
function actually works.
2.3 (29 Jan 2012)
=================
* When adding data, auto-select the more efficient encoding methods for numbers
and alphanumeric data (KANJI still not supported).
2.3.1
-----
* Encode unicode to utf-8 bytestrings when adding data to a QRCode.
2.2 (18 Jan 2012)
=================
* Fixed tty output to work on both white and black backgrounds.
* Added `border` parameter to allow customizing of the number of boxes used to
create the border of the QR code
2.1 (17 Jan 2012)
=================
* Added a ``qr`` script which can be used to output a qr code to the tty using
background colors, or to a file via a pipe.