`libqrencode.qrencode` – QR Encoding¶

Python ctypes binding to libqrencode.

This module when ran as a script attempts to mimic the c sample program qrenc.c otherwise known as qrencode

This file is part of libqrencode python ctypes bindings.

This is free software: you can redistribute it and/or modify it under the terms of the LGNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the LGNU Lesser General Public License along with this software. If not, see <http://www.gnu.org/licenses/>.

Installation¶

Install libqrencode.
Unpack archive onto local machine.
Run
```
$ python setup.py install
```

Test

$ python -m libqrencode.qrencode 'Hello World'
XXXXXXXXXXXXXX    XX  XXXX  XXXXXXXXXXXXXX
XX          XX    XXXXXX    XX          XX
XX  XXXXXX  XX  XXXX  XXXX  XX  XXXXXX  XX
XX  XXXXXX  XX    XX  XX    XX  XXXXXX  XX
XX  XXXXXX  XX      XX  XX  XX  XXXXXX  XX
XX          XX          XX  XX          XX
XXXXXXXXXXXXXX  XX  XX  XX  XXXXXXXXXXXXXX
                XXXX  XXXX
XXXXXX  XXXXXXXXXXXXXXXX  XXXX      XX
  XXXX  XXXX    XXXXXX      XXXXXX    XXXX
XX  XX  XX  XX  XX  XX  XXXX  XXXXXXXXXXXX
    XX          XXXXXX          XX    XX
XXXX    XX  XXXX  XX    XXXX  XXXX
                XX  XXXX  XX        XXXX
XXXXXXXXXXXXXX  XX  XXXX      XXXX  XXXXXX
XX          XX  XXXX  XXXX    XX        XX
XX  XXXXXX  XX  XX    XX        XX
XX  XXXXXX  XX    XXXXXX    XXXXXX  XXXX
XX  XXXXXX  XX  XX  XX  XX  XX  XX  XX  XX
XX          XX  XX    XX        XX    XX
XXXXXXXXXXXXXX  XX  XXXXXX    XX      XXXX

Usage¶

Scripted Usage¶

Run the following for usage

$ python -m libqrencode.qrencode -h
Usage: qrencode [OPTION]... [STRING]

libqrencode ctypes python binding version 1.0, libqrencode version 3.2.1

Options:
  -h, --help            show this help message and exit
  -o FILENAME, --filename=FILENAME
                        Encoded image filename (.png, .pdf, .jpg, .tif...)
  -s SIZE, --size=SIZE  Specify module size in dots (pixels). (default=3)
  -l LEVEL, --level=LEVEL
                        specify error correction level from L (lowest) to H
                        (highest). (default=L)
  -v SYMVERSION, --symversion=SYMVERSION
                        specify the version of the symbol. (default=auto)
  -m MARGIN, --margin=MARGIN
                        specify the width of the margins. (default=4)
                        (2 for Micro)))
  -d DPI, --dpi=DPI     specify the DPI of the generated PNG. (default=72)
  -S, --structured      make structured symbols. Version must be
                        specified.
  -k, --kanji           assume that the input text contains kanji
                        (shift-jis).
  -c, --casesensitive   encode lower-case alphabet characters in 8-bit mode.
                        (default)
  -8, --eightbit        encode entire data in 8-bit mode. -k and -c will be
                        ignored.
  -M, --micro           encode in a Micro QR Code. (experimental).

Module Usage¶

Import libqrencode bindings:
```
>>> from libqrencode import qrencode
```
Create a qrencode.QREncoder instantiation:
```
>>> encoder = qrencode.QREncoder()
```
Encode a string using the aforementioned instantiation:
```
>>> encoder.encode('Hello World')
```

Select encoded output format from one of the following output formats:

ASCII:

>>> encoder.asciipreview()
XXXXXXXXXXXXXX    XX  XXXX  XXXXXXXXXXXXXX
XX          XX    XXXXXX    XX          XX
XX  XXXXXX  XX  XXXX  XXXX  XX  XXXXXX  XX
XX  XXXXXX  XX    XX  XX    XX  XXXXXX  XX
XX  XXXXXX  XX      XX  XX  XX  XXXXXX  XX
XX          XX          XX  XX          XX
XXXXXXXXXXXXXX  XX  XX  XX  XXXXXXXXXXXXXX
                XXXX  XXXX
XXXXXX  XXXXXXXXXXXXXXXX  XXXX      XX
  XXXX  XXXX    XXXXXX      XXXXXX    XXXX
XX  XX  XX  XX  XX  XX  XXXX  XXXXXXXXXXXX
    XX          XXXXXX          XX    XX
XXXX    XX  XXXX  XX    XXXX  XXXX
                XX  XXXX  XX        XXXX
XXXXXXXXXXXXXX  XX  XXXX      XXXX  XXXXXX
XX          XX  XXXX  XXXX    XX        XX
XX  XXXXXX  XX  XX    XX        XX
XX  XXXXXX  XX    XXXXXX    XXXXXX  XXXX
XX  XXXXXX  XX  XX  XX  XX  XX  XX  XX  XX
XX          XX  XX    XX        XX    XX
XXXXXXXXXXXXXX  XX  XXXXXX    XX      XXXX

Boolean list of lists:
```
>>> qr_list = encoder.as2dlist()
```
Postscript string:
```
>>> qr_ps = encoder.asps()
```

See the individual classes, methods, attributes and functions below for further details.

Classes¶

class libqrencode.qrencode.QREncode(p)[source]¶: Base class for representing QREncode c structures. Allows for struct member read access as class attributes.

class libqrencode.qrencode.QRcode(p, cleanup=True)[source]¶: Python representation of QRcode c structure

class libqrencode.qrencode.QRcode_List(p)[source]¶: Python representation of QRcode_List c structure.

class libqrencode.qrencode.QREncoder[source]¶

Base class for representing QREncoder.

Largely used to maintain the state that the globals in qrenc.c represent.

as2dlist()[source]¶: Return a list of lists describing the encoded data.

asciipreview()[source]¶: Print an ascii representation of the Encoder output to stdout

asps()[source]¶

Return a PostScript representation of the encoded QRCode.

Paints the “black” symbol in the current colour on the assumption that the background has already been painted and appropriate colour. Symbols are assumed to be 1 user coordinate square.

casesensitive¶: Return the QREncoder’s casesensitive property.

code¶: Return the QREncode object

eightbit¶: Return the QREncoder’s eightbit property.

encode(data)[source]¶: Encode input string represented by data

hint¶: Return the QREncoder’s hint.

level¶: Return the QREncoder’s level.

micro¶: Return the QREncoder’s micro property.

version¶: Return the QREncoder’s symbol version property.

class libqrencode.qrencode.StructuredQREncoder[source]¶

Subclassing of QREncoder for structured QR encoding.

as2dlists()[source]¶: Return a list of list of lists describing the encoded data.

asciipreview()[source]¶: Print an ascii representation of the Encoder output to stdout

asps()[source]¶: Return a list of PostScript strings representing the encoded QRCode’s of the StructuredQREncoder.

code_list¶: Return StructuredQREncoder’s code_list.

encode(data)[source]¶: Encode input string represented by data

Functions¶

libqrencode.qrencode.call(func, *args)[source]¶: Convenience routine to call function func, check for NULL pointer and subsequently check errno to report useful error message.

libqrencode.qrencode.main(argv)[source]¶

Exceptions¶

exception libqrencode.qrencode.Error[source]¶: This is a user-defined exception for errors raised by this module.

Pre-requisites¶

Python (http://www.python.org)

libqrencode (http://fukuchi.org/works/qrencode/index.html.en)

Python Imaging Library (PIL, http://www.pythonware.com/products/pil/) (optional)

Known Issues¶

For the moment the bindings have only be constructed for use under linux. I could be tempted to support windows if required.

`libqrencode.qrencode` – QR Encoding¶

Installation¶

Usage¶

Scripted Usage¶

Module Usage¶

Classes¶

Functions¶

Exceptions¶

Pre-requisites¶

Known Issues¶

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libqrencode.qrencode – QR Encoding¶

Installation¶

Usage¶

Scripted Usage¶

Module Usage¶

Classes¶

Functions¶

Exceptions¶

Pre-requisites¶

Known Issues¶

Table Of Contents

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`libqrencode.qrencode` – QR Encoding¶