treepoem 3.1.0

Barcode rendering for Python 2 and 3 supporting QRcode, Aztec, PDF417, I25, Code128, Code39 and many more types.

A cleverly named, but very simple python barcode renderer wrapping the BWIPP library and ghostscript command line tool.

Installation

Install from pip:

pip install treepoem

Python 3.5-3.7 supported.

You’ll also need Ghostscript installed. On Ubuntu/Debian this can be installed with:

apt-get install ghostscript

On Mac OS X use:

brew install ghostscript

Otherwise refer to your distribution’s package manager, though it’s likely to be called ghostscript too.

There’s a known issue with rendering on Ghostscript 9.22+ where images are smeared. See GitHub Issue #124 and its associated links for more details. Ghostscript merged a fix in version 9.26 and common barcodes seem to work from then on, though still with some smearing.

You can check your Ghostscript version with:

gs --version

API

generate_barcode(barcode_type, data, options=None)

Generates a barcode and returns it as a PIL image file object (specifically, a PIL.EpsImagePlugin.EpsImageFile).

barcode_type is the name of the barcode type to generate (see below).

data is a str (Python 2 unicode) or bytes (Python 2 bytes) of data to embed in the barcode - the amount that can be embedded varies by type.

options is a dictionary of strings-to-strings of extra options to be passed to BWIPP, as per its docs.

For example, this generates a QR code image, and saves it to a file using standard PIL Image.save():

>>> import treepoem
>>> image = treepoem.generate_barcode(
...     barcode_type='qrcode',  # One of the BWIPP supported codes.
...     data='barcode payload',
... )
>>> image.convert('1').save('barcode.png')

If your barcode image is monochrome, with no additional text or coloring, converting the Image object to monochrome as shown above (image.convert('1')) will likely reduce its file size.

barcode_types

This is a dict of the ~100 names of the barcode types that the vendored version of BWIPP supports: its keys are strs of the barcode type encoder names, and the values are instances of BarcodeType.

BarcodeType

A class representing meta information on the types. It has two attributes:

• type_code - the value needed for the barcode_type argument of generate_barcode() to use this type.
• description - the human level description of the type which has two str.

Only these common types are used in the test suite:

• qrcode - QR Code
• azteccode - Aztec Code
• pdf417 - PDF417
• interleaved2of5 - Interleaved 2 of 5
• code128 - Code 128
• code39 - Code 39

Command-line interface

Treepoem also includes a simple command-line interface to the functionality of generate_barcode. For example, these commands will generate two QR codes with identical contents, but different levels of error correction (see QR Code Options):

$ treepoem -o barcode1.png -t qrcode "This is a test" eclevel=H
$ treepoem -o barcode2.png -t qrcode "^084his is a test" eclevel=L parse

Complete usage instructions are shown with treepoem --help.

What’s so clever about the name?

Barcode.

Bark ode.

Tree poem.

History

3.1.0 (2019-06-25)

• Update Python support to 3.5-3.7, as 3.4 has reached its end of life.
• Upgrade BWIPP from 2017-07-27 to 2019-04-24. This has a few bug fixes and performance improvements. You can read its changelog in the vendored copy in the treepoem repo.

3.0.0 (2019-05-08)

• Drop Python 2 support, only Python 3.4+ is supported now.
• Upgrade BWIPP from 2017-05-20 to 2018-07-27. This has a few bug fixes and performance improvements. You can read its changelog in the vendored copy in the treepoem repo.

2.0.0 (2018-08-04)

• Support binary barcode data - if bytes (str on Python 2) is passed as data, it’s not encoded. This has introduced a dependency on six. This may be backwards incompatible, depending on what type of data you’re passing in on Python 2.
• Make treepoem.barcode_types a dict mapping the BWIPP encoder names to a custom type containing a human-readable description. This is backwards incompatible if you’re relying on barcode_types which previously was a set of the encoder names.
• Upgrade BWIPP from 2017-10-19 to 2018-05-20. This has a few bug fixes and performance improvements. You can read its changelog in the vendored copy in the treepoem repo.

1.4.1 (2018-05-01)

• Fix formatting bug in CLI output.

1.4.0 (2018-05-01)

• Make the options argument to generate_barcode optional.
• Add a CLI treepoem.
• Upgrade BWIPP from 2017-07-10 to 2017-10-19. This has a few bug fixes and performance improvements. You can read its changelog in the vendored copy in the treepoem repo.

1.3.2 (2017-10-22)

• Upgrade BWIPP from 2017-07-10 to 2017-10-19. This has a few bug fixes. You can read its changelog in the vendored copy in the treepoem repo.

1.3.1 (2017-08-24)

• Upgrade BWIPP from 2017-06-20 to 2017-07-10. This has a few bug fixes. You can read its changelog in the vendored copy in the treepoem repo.

1.3.0 (2017-06-21)

• Upgrade BWIPP from 2015-11-24 to 2017-06-20. This has a number of bug fixes, and supports more barcode types. It has also changed the pixel-for-pixel output of some formats, although they still encode the same information - notably QR codes, which are tested in treepoem’s test suite. You can read its changelog in the vendored copy in the treepoem repo.

1.2.0 (2017-06-21)

• Add treepoem.barcode_types, a set of all the names of supported barcode types, and error if asked to generate a barcode of an unknown type.

1.1.0 (2017-04-13)

• Support Windows.

1.0.1 (2016-03-30)

• Add the missing BWIPP files.

1.0.0 (2016-03-23)

• Use $PATH to find gs binary.
• Rename PostscriptError to TreepoemError.
• Add basic setup.py.
• Setup Travis CI build.
• Setup Tox