python-escpos/doc/user/barcode.rst

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Printing Barcodes
-----------------
:Last Reviewed: 2023-05-16
Many printers implement barcode printing natively.
This hardware renderered barcodes are fast but the supported formats are limited by the printer itself and different between models.
However, almost all printers support printing images, so barcode renderization can be performed externally by software and then sent to the printer as an image.
As a drawback, this operation is much slower and the user needs to know and choose the image implementation method supported by the printer's commandset.
barcode-method
~~~~~~~~~~~~~~
Since version 3.0, the ``barcode`` method unifies the previous ``barcode`` (hardware) and ``soft_barcode`` (software) methods.
It is able to choose automatically the best printer implementation for barcode printing based on the capabilities of the printer and the type of barcode desired.
To achieve this, it relies on the information contained in the escpos-printer-db profiles.
The chosen profile needs to match the capabilities of the printer as closely as possible.
.. py:currentmodule:: escpos.escpos
.. automethod:: Escpos.barcode
:noindex:
CODE128
~~~~~~~
Code128 barcodes need a certain format.
For now the user has to make sure that the payload is correct.
For alphanumeric CODE128 you have to preface your payload with `{B`.
.. code-block:: Python
from escpos.printer import Dummy, Serial
p = Serial()
# print CODE128 012ABCDabcd
p.barcode("{B012ABCDabcd", "CODE128", function_type="B")
A very good description on CODE128 is also on `Wikipedia <https://en.wikipedia.org/wiki/Code_128>`_.