# -*- coding: utf-8 -*-
# Copyright (c) 2013, Michael Nooner
# All rights reserved.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the copyright holder nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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"""This module is used to create QR Codes. It is designed to be as simple and
as possible. It does this by using sane defaults and autodetection to make
creating a QR Code very simple.
It is recommended that you use the :func:`pyqrcode.create` function to build the
QRCode object. This results in cleaner looking code.
Examples:
>>> import pyqrcode
>>> import sys
>>> url = pyqrcode.create('http://uca.edu')
>>> url.svg(sys.stdout, scale=1)
>>> url.svg('uca.svg', scale=4)
>>> number = pyqrcode.create(123456789012345)
>>> number.png('big-number.png')
"""
#Imports required for 2.7 support
from __future__ import absolute_import, division, print_function, with_statement, unicode_literals
import pyqrcode.tables
import pyqrcode.builder as builder
try:
str = unicode # Python 2
except NameError:
pass
[docs]def create(content, error='H', version=None, mode=None, encoding=None):
"""When creating a QR code only the content to be encoded is required,
all the other properties of the code will be guessed based on the
contents given. This function will return a :class:`QRCode` object.
Unless you are familiar with QR code's inner workings
it is recommended that you just specify the *content* and nothing else.
However, there are cases where you may want to specify the various
properties of the created code manually, this is what the other
parameters do. Below, you will find a lengthy explanation of what
each parameter is for. Note, the parameter names and values are taken
directly from the standards. You may need to familiarize yourself
with the terminology of QR codes for the names and their values to
make sense.
The *error* parameter sets the error correction level of the code. There
are four levels defined by the standard. The first is level 'L' which
allows for 7% of the code to be corrected. Second, is level 'M' which
allows for 15% of the code to be corrected. Next, is level 'Q' which
is the most common choice for error correction, it allow 25% of the
code to be corrected. Finally, there is the highest level 'H' which
allows for 30% of the code to be corrected. There are several ways to
specify this parameter, you can use an upper or lower case letter,
a float corresponding to the percentage of correction, or a string
containing the percentage. See tables.modes for all the possible
values. By default this parameter is set to 'H' which is the highest
possible error correction, but it has the smallest available data
capacity.
The *version* parameter specifies the size and data capacity of the
code. Versions are any integer between 1 and 40. Where version 1 is
the smallest QR code, and version 40 is the largest. If this parameter
is left unspecified, then the contents and error correction level will
be used to guess the smallest possible QR code version that the
content will fit inside of. You may want to specify this parameter
for consistency when generating several QR codes with varying amounts
of data. That way all of the generated codes would have the same size.
The *mode* parameter specifies how the contents will be encoded. By
default, the best possible mode for the contents is guessed. There
are four possible modes. First, is 'numeric' which is
used to encode integer numbers. Next, is 'alphanumeric' which is
used to encode some ASCII characters. This mode uses only a limited
set of characters. Most problematic is that it can only use upper case
English characters, consequently, the content parameter will be
subjected to str.upper() before encoding. See tables.ascii_codes for
a complete list of available characters. The is 'kanji' mode can be
used for Japanese characters, but only those that can be understood
via the shift-jis string encoding. Finally, we then have 'binary' mode
which just encodes the bytes directly into the QR code (this encoding
is the least efficient).
The *encoding* parameter specifies how the content will be interpreted.
This parameter only matters if the *content* is a string, unicode, or
byte array type. This parameter must be a valid encoding string or None.
t will be passed the *content*'s encode/decode methods.
"""
return QRCode(content, error, version, mode, encoding)
[docs]class QRCode:
"""This class represents a QR code. To use this class simply give the
constructor a string representing the data to be encoded, it will then
build a code in memory. You can then save it in various formats. Note,
codes can be written out as PNG files but this requires the PyPNG module.
You can find the PyPNG module at http://packages.python.org/pypng/.
Examples:
>>> from pyqrcode import QRCode
>>> import sys
>>> url = QRCode('http://uca.edu')
>>> url.svg(sys.stdout, scale=1)
>>> url.svg('uca.svg', scale=4)
>>> number = QRCode(123456789012345)
>>> number.png('big-number.png')
.. note::
For what all of the parameters do, see the :func:`pyqrcode.create`
function.
"""
def __init__(self, content, error='H', version=None, mode=None,
encoding='iso-8859-1'):
#Guess the mode of the code, this will also be used for
#error checking
guessed_content_type, encoding = self._detect_content_type(content, encoding)
if encoding is None:
encoding = 'iso-8859-1'
#Store the encoding for use later
if guessed_content_type == 'kanji':
self.encoding = 'shiftjis'
else:
self.encoding = encoding
if version is not None:
if 1 <= version <= 40:
self.version = version
else:
raise ValueError("Illegal version {0}, version must be between "
"1 and 40.".format(version))
#Decode a 'byte array' contents into a string format
if isinstance(content, bytes):
self.data = content.decode(encoding)
#Give a string an encoding
elif hasattr(content, 'encode'):
self.data = content.encode(self.encoding)
#The contents are not a byte array or string, so
#try naively converting to a string representation.
else:
self.data = str(content) # str == unicode in Py 2.x, see file head
#Force a passed in mode to be lowercase
if hasattr(mode, 'lower'):
mode = mode.lower()
#Check that the mode parameter is compatible with the contents
if mode is None:
#Use the guessed mode
self.mode = guessed_content_type
self.mode_num = tables.modes[self.mode]
elif mode not in tables.modes.keys():
#Unknown mode
raise ValueError('{0} is not a valid mode.'.format(mode))
elif guessed_content_type == 'binary' and \
tables.modes[mode] != tables.modes['binary']:
#Binary is only guessed as a last resort, if the
#passed in mode is not binary the data won't encode
raise ValueError('The content provided cannot be encoded with '
'the mode {}, it can only be encoded as '
'binary.'.format(mode))
elif tables.modes[mode] == tables.modes['numeric'] and \
guessed_content_type != 'numeric':
#If numeric encoding is requested make sure the data can
#be encoded in that format
raise ValueError('The content cannot be encoded as numeric.')
elif tables.modes[mode] == tables.modes['kanji'] and \
guessed_content_type != 'kanji':
raise ValueError('The content cannot be encoded as kanji.')
else:
#The data should encode with the passed in mode
self.mode = mode
self.mode_num = tables.modes[self.mode]
#Check that the user passed in a valid error level
if error in tables.error_level.keys():
self.error = tables.error_level[error]
else:
raise ValueError('{0} is not a valid error '
'level.'.format(error))
#Guess the "best" version
self.version = self._pick_best_fit(self.data)
#If the user supplied a version, then check that it has
#sufficient data capacity for the contents passed in
if version:
if version >= self.version:
self.version = version
else:
raise ValueError('The data will not fit inside a version {} '
'code with the given encoding and error '
'level (the code must be at least a '
'version {}).'.format(version, self.version))
#Build the QR code
self.builder = builder.QRCodeBuilder(data=self.data,
version=self.version,
mode=self.mode,
error=self.error)
#Save the code for easier reference
self.code = self.builder.code
def __str__(self):
return repr(self)
def __unicode__(self):
return self.__repr__()
def __repr__(self):
return "QRCode(content={0}, error='{1}', version={2}, mode='{3}')" \
.format(repr(self.data), self.error, self.version, self.mode)
def _detect_content_type(self, content, encoding):
"""This method tries to auto-detect the type of the data. It first
tries to see if the data is a valid integer, in which case it returns
numeric. Next, it tests the data to see if it is 'alphanumeric.' QR
Codes use a special table with very limited range of ASCII characters.
The code's data is tested to make sure it fits inside this limited
range. If all else fails, the data is determined to be of type
'binary.'
Returns a tuple containing the detected mode and encoding.
Note, encoding ECI is not yet implemented.
"""
def two_bytes(c):
"""Output two byte character code as a single integer."""
def next_byte(b):
"""Make sure that character code is an int. Python 2 and
3 compatibility.
"""
if not isinstance(b, int):
return ord(b)
else:
return b
#Go through the data by looping to every other character
for i in range(0, len(c), 2):
yield (next_byte(c[i]) << 8) | next_byte(c[i+1])
#See if the data is a number
try:
if str(content).isdigit():
return 'numeric', encoding
except (TypeError, UnicodeError):
pass
#See if that data is alphanumeric based on the standards
#special ASCII table
valid_characters = ''.join(tables.ascii_codes.keys())
#Force the characters into a byte array
valid_characters = valid_characters.encode('ASCII')
try:
if isinstance(content, bytes):
c = content.decode('ASCII')
else:
c = str(content).encode('ASCII')
if all(map(lambda x: x in valid_characters, c)):
return 'alphanumeric', 'ASCII'
#This occurs if the content does not contain ASCII characters.
#Since the whole point of the if statement is to look for ASCII
#characters, the resulting mode should not be alphanumeric.
#Hence, this is not an error.
except TypeError:
pass
except UnicodeError:
pass
try:
if isinstance(content, bytes):
if encoding is None:
encoding = 'shiftjis'
c = content.decode(encoding).encode('shiftjis')
else:
c = content.encode('shiftjis')
#All kanji characters must be two bytes long, make sure the
#string length is not odd.
if len(c) % 2 != 0:
return 'binary', encoding
#Make sure the characters are actually in range.
for asint in two_bytes(c):
#Shift the two byte value as indicated by the standard
if not (0x8140 <= asint <= 0x9FFC or
0xE040 <= asint <= 0xEBBF):
return 'binary', encoding
return 'kanji', encoding
except UnicodeError:
#This occurs if the content does not contain Shift JIS kanji
#characters. Hence, the resulting mode should not be kanji.
#This is not an error.
pass
#All of the other attempts failed. The content can only be binary.
return 'binary', encoding
def _pick_best_fit(self, content):
"""This method return the smallest possible QR code version number
that will fit the specified data with the given error level.
"""
import math
for version in range(1, 41):
#Get the maximum possible capacity
capacity = tables.data_capacity[version][self.error][self.mode_num]
#Check the capacity
#Kanji's count in the table is "characters" which are two bytes
if (self.mode_num == tables.modes['kanji'] and
capacity >= math.ceil(len(content) / 2)):
return version
if capacity >= len(content):
return version
raise ValueError('The data will not fit in any QR code version '
'with the given encoding and error level.')
[docs] def show(self, wait=1.2, scale=10, module_color=(0, 0, 0, 255),
background=(255, 255, 255, 255), quiet_zone=4):
"""Displays this QR code.
This method is mainly intended for debugging purposes.
This method saves the output of the :py:meth:`png` method (with a default
scaling factor of 10) to a temporary file and opens it with the
standard PNG viewer application or within the standard webbrowser. The
temporary file is deleted afterwards.
If this method does not show any result, try to increase the `wait`
parameter. This parameter specifies the time in seconds to wait till
the temporary file is deleted. Note, that this method does not return
until the provided amount of seconds (default: 1.2) has passed.
The other parameters are simply passed on to the `png` method.
"""
import os
import time
import tempfile
import webbrowser
try: # Python 2
from urlparse import urljoin
from urllib import pathname2url
except ImportError: # Python 3
from urllib.parse import urljoin
from urllib.request import pathname2url
f = tempfile.NamedTemporaryFile('wb', suffix='.png', delete=False)
self.png(f, scale=scale, module_color=module_color,
background=background, quiet_zone=quiet_zone)
f.close()
webbrowser.open_new_tab(urljoin('file:', pathname2url(f.name)))
time.sleep(wait)
os.unlink(f.name)
[docs] def get_png_size(self, scale=1, quiet_zone=4):
"""This is method helps users determine what *scale* to use when
creating a PNG of this QR code. It is meant mostly to be used in the
console to help the user determine the pixel size of the code
using various scales.
This method will return an integer representing the width and height of
the QR code in pixels, as if it was drawn using the given *scale*.
Because QR codes are square, the number represents both the width
and height dimensions.
The *quiet_zone* parameter sets how wide the quiet zone around the code
should be. According to the standard this should be 4 modules. It is
left settable because such a wide quiet zone is unnecessary in many
applications where the QR code is not being printed.
Example:
>>> code = pyqrcode.QRCode("I don't like spam!")
>>> print(code.get_png_size(1))
31
>>> print(code.get_png_size(5))
155
"""
return builder._get_png_size(self.version, scale, quiet_zone)
[docs] def png(self, file, scale=1, module_color=(0, 0, 0, 255),
background=(255, 255, 255, 255), quiet_zone=4):
"""This method writes the QR code out as an PNG image. The resulting
PNG has a bit depth of 1. The file parameter is used to specify where
to write the image to. It can either be an writable stream or a
file path.
.. note::
This method depends on the pypng module to actually create the
PNG file.
This method will write the given *file* out as a PNG file. The file
can be either a string file path, or a writable stream. The file
will not be automatically closed if a stream is given.
The *scale* parameter sets how large to draw a single module. By
default one pixel is used to draw a single module. This may make the
code too small to be read efficiently. Increasing the scale will make
the code larger. Only integer scales are usable. This method will
attempt to coerce the parameter into an integer (e.g. 2.5 will become 2,
and '3' will become 3). You can use the :py:meth:`get_png_size` method
to calculate the actual pixel size of the resulting PNG image.
The *module_color* parameter sets what color to use for the encoded
modules (the black part on most QR codes). The *background* parameter
sets what color to use for the background (the white part on most
QR codes). If either parameter is set, then both must be
set or a ValueError is raised. Colors should be specified as either
a list or a tuple of length 3 or 4. The components of the list must
be integers between 0 and 255. The first three member give the RGB
color. The fourth member gives the alpha component, where 0 is
transparent and 255 is opaque. Note, many color
combinations are unreadable by scanners, so be judicious.
The *quiet_zone* parameter sets how wide the quiet zone around the code
should be. According to the standard this should be 4 modules. It is
left settable because such a wide quiet zone is unnecessary in many
applications where the QR code is not being printed.
Example:
>>> code = pyqrcode.create('Are you suggesting coconuts migrate?')
>>> code.png('swallow.png', scale=5)
>>> code.png('swallow.png', scale=5,
module_color=(0x66, 0x33, 0x0), #Dark brown
background=(0xff, 0xff, 0xff, 0x88)) #50% transparent white
"""
builder._png(self.code, self.version, file, scale,
module_color, background, quiet_zone)
[docs] def png_as_base64_str(self, scale=1, module_color=(0, 0, 0, 255),
background=(255, 255, 255, 255), quiet_zone=4):
"""This method uses the png render and returns the PNG image encoded as
base64 string. This can be useful for creating dynamic PNG images for
web development, since no file needs to be created.
Example:
>>> code = pyqrcode.create('Are you suggesting coconuts migrate?')
>>> image_as_str = code.png_as_base64_str(scale=5)
>>> html_img = '<img src="data:image/png;base64,{}">'.format(image_as_str)
The parameters are passed directly to the :py:meth:`png` method. Refer
to that method's documentation for the meaning behind the parameters.
.. note::
This method depends on the pypng module to actually create the
PNG image.
"""
import io
import base64
with io.BytesIO() as virtual_file:
self.png(file=virtual_file, scale=scale, module_color=module_color,
background=background, quiet_zone=quiet_zone)
image_as_str = base64.b64encode(virtual_file.getvalue()).decode("ascii")
return image_as_str
[docs] def xbm(self, scale=1, quiet_zone=4):
"""Returns a string representing an XBM image of the QR code.
The XBM format is a black and white image format that looks like a
C header file.
Because displaying QR codes in Tkinter is the
primary use case for this renderer, this method does not take a file
parameter. Instead it retuns the rendered QR code data as a string.
Example of using this renderer with Tkinter:
>>> import pyqrcode
>>> import tkinter
>>> code = pyqrcode.create('Knights who say ni!')
>>> code_xbm = code.xbm(scale=5)
>>>
>>> top = tkinter.Tk()
>>> code_bmp = tkinter.BitmapImage(data=code_xbm)
>>> code_bmp.config(foreground="black")
>>> code_bmp.config(background="white")
>>> label = tkinter.Label(image=code_bmp)
>>> label.pack()
The *scale* parameter sets how large to draw a single module. By
default one pixel is used to draw a single module. This may make the
code too small to be read efficiently. Increasing the scale will make
the code larger. Only integer scales are usable. This method will
attempt to coerce the parameter into an integer (e.g. 2.5 will become 2,
and '3' will become 3). You can use the :py:meth:`get_png_size` method
to calculate the actual pixel size of this image when displayed.
The *quiet_zone* parameter sets how wide the quiet zone around the code
should be. According to the standard this should be 4 modules. It is
left settable because such a wide quiet zone is unnecessary in many
applications where the QR code is not being printed.
"""
return builder._xbm(self.code, scale, quiet_zone)
[docs] def svg(self, file, scale=1, module_color='#000', background=None,
quiet_zone=4, xmldecl=True, svgns=True, title=None,
svgclass='pyqrcode', lineclass='pyqrline', omithw=False,
debug=False):
"""This method writes the QR code out as an SVG document. The
code is drawn by drawing only the modules corresponding to a 1. They
are drawn using a line, such that contiguous modules in a row
are drawn with a single line.
The *file* parameter is used to specify where to write the document
to. It can either be a writable stream or a file path.
The *scale* parameter sets how large to draw
a single module. By default one pixel is used to draw a single
module. This may make the code too small to be read efficiently.
Increasing the scale will make the code larger. Unlike the png() method,
this method will accept fractional scales (e.g. 2.5).
Note, three things are done to make the code more appropriate for
embedding in a HTML document. The "white" part of the code is actually
transparent. The code itself has a class given by *svgclass* parameter.
The path making up the QR code uses the class set using the *lineclass*.
These should make the code easier to style using CSS.
By default the output of this function is a complete SVG document. If
only the code itself is desired, set the *xmldecl* to false. This will
result in a fragment that contains only the "drawn" portion of the code.
Likewise, you can set the *title* of the document. The SVG name space
attribute can be suppressed by setting *svgns* to False.
When True the *omithw* indicates if width and height attributes should
be omitted. If these attributes are omitted, a ``viewBox`` attribute
will be added to the document.
You can also set the colors directly using the *module_color* and
*background* parameters. The *module_color* parameter sets what color to
use for the data modules (the black part on most QR codes). The
*background* parameter sets what color to use for the background (the
white part on most QR codes). The parameters can be set to any valid
SVG or HTML color. If the background is set to None, then no background
will be drawn, i.e. the background will be transparent. Note, many color
combinations are unreadable by scanners, so be careful.
The *quiet_zone* parameter sets how wide the quiet zone around the code
should be. According to the standard this should be 4 modules. It is
left settable because such a wide quiet zone is unnecessary in many
applications where the QR code is not being printed.
Example:
>>> code = pyqrcode.create('Hello. Uhh, can we have your liver?')
>>> code.svg('live-organ-transplants.svg', 3.6)
>>> code.svg('live-organ-transplants.svg', scale=4,
module_color='brown', background='0xFFFFFF')
"""
builder._svg(self.code, self.version, file, scale=scale,
module_color=module_color, background=background,
quiet_zone=quiet_zone, xmldecl=xmldecl, svgns=svgns,
title=title, svgclass=svgclass, lineclass=lineclass,
omithw=omithw, debug=debug)
[docs] def eps(self, file, scale=1, module_color=(0, 0, 0),
background=None, quiet_zone=4):
"""This method writes the QR code out as an EPS document. The
code is drawn by only writing the data modules corresponding to a 1.
They are drawn using a line, such that contiguous modules in a row
are drawn with a single line.
The *file* parameter is used to specify where to write the document
to. It can either be a writable (text) stream or a file path.
The *scale* parameter sets how large to draw a single module. By
default one point (1/72 inch) is used to draw a single module. This may
make the code to small to be read efficiently. Increasing the scale
will make the code larger. This method will accept fractional scales
(e.g. 2.5).
The *module_color* parameter sets the color of the data modules. The
*background* parameter sets the background (page) color to use. They
are specified as either a triple of floats, e.g. (0.5, 0.5, 0.5), or a
triple of integers, e.g. (128, 128, 128). The default *module_color* is
black. The default *background* color is no background at all.
The *quiet_zone* parameter sets how large to draw the border around
the code. As per the standard, the default value is 4 modules.
Examples:
>>> qr = pyqrcode.create('Hello world')
>>> qr.eps('hello-world.eps', scale=2.5, module_color='#36C')
>>> qr.eps('hello-world2.eps', background='#eee')
>>> out = io.StringIO()
>>> qr.eps(out, module_color=(.4, .4, .4))
"""
builder._eps(self.code, self.version, file, scale, module_color,
background, quiet_zone)
[docs] def terminal(self, module_color='default', background='reverse',
quiet_zone=4):
"""This method returns a string containing ASCII escape codes,
such that if printed to a compatible terminal, it will display
a vaild QR code. The code is printed using ASCII escape
codes that alter the coloring of the background.
The *module_color* parameter sets what color to
use for the data modules (the black part on most QR codes).
Likewise, the *background* parameter sets what color to use
for the background (the white part on most QR codes).
There are two options for colors. The first, and most widely
supported, is to use the 8 or 16 color scheme. This scheme uses
eight to sixteen named colors. The following colors are
supported the most widely supported: black, red, green,
yellow, blue, magenta, and cyan. There are an some additional
named colors that are supported by most terminals: light gray,
dark gray, light red, light green, light blue, light yellow,
light magenta, light cyan, and white.
There are two special named colors. The first is the
"default" color. This color is the color the background of
the terminal is set to. The next color is the "reverse"
color. This is not really a color at all but a special
property that will reverse the current color. These two colors
are the default values for *module_color* and *background*
respectively. These values should work on most terminals.
Finally, there is one more way to specify the color. Some
terminals support 256 colors. The actual colors displayed in the
terminal is system dependent. This is the least transportable option.
To use the 256 color scheme set *module_color* and/or
*background* to a number between 0 and 256.
The *quiet_zone* parameter sets how wide the quiet zone around the code
should be. According to the standard this should be 4 modules. It is
left settable because such a wide quiet zone is unnecessary in many
applications.
Example:
>>> code = pyqrcode.create('Example')
>>> text = code.terminal()
>>> print(text)
"""
return builder._terminal(self.code, module_color, background,
quiet_zone)
[docs] def text(self, quiet_zone=4):
"""This method returns a string based representation of the QR code.
The data modules are represented by 1's and the background modules are
represented by 0's. The main purpose of this method is to act a
starting point for users to create their own renderers.
The *quiet_zone* parameter sets how wide the quiet zone around the code
should be. According to the standard this should be 4 modules. It is
left settable because such a wide quiet zone is unnecessary in many
applications.
Example:
>>> code = pyqrcode.create('Example')
>>> text = code.text()
>>> print(text)
"""
return builder._text(self.code, quiet_zone)
![[docs]](../moddoc.html#pyqrcode.QRCode.png){kind=link}
![[docs]](../moddoc.html#pyqrcode.QRCode.svg){kind=link}