[Brother QL-570] Black Square Printout about brother_ql

[nmaas87]

Absolutely awesome! It works like a treat! 👍 Thanks a lot for the very quick help!
Do you have any intention to make that program into a kind of Python API, so that you could call it as a function with an file and the needed variables to include that in own software? (It ain't needed, as one can really fastly call it via shell commands and such, but just as a question :)!)

[pklaus]

Thanks for the bug report. This issue should be fixed in 743d963. Please upgrade and test again.

[pklaus]

By the way: The errors in brother_ql_print show that you are using it with Python 2. It was not made for this.
I spent some work to make brother_ql_create work with Python 2, however (which is why it worked at all). You can simply print by using cat cafe.bin > /dev/usb/lp0 instead of brother_ql_print.

[pklaus]

Do you have any intention to make that program into a kind of Python API, so that you could call it as a function with an file and the needed variables to include that in own software?

You can do:

from brother_ql import BrotherQLRaster, create_label
qlr = BrotherQLRaster("QL-570")
# image can be a PIL/Pillow Image() object or a file name to the GIF/PNG/JPEG image:
create_label(qlr, image, "62", threshold=70, cut=True)
# The binary image output is then available in this variable:
qlr.data

You can send this to your printer via simple Python:

import os
dev = os.open('/dev/usb/lp0', os.O_RDWR)
try:
    data = os.write(dev, qlr.data)
except KeyboardInterrupt:
    pass
finally:
    os.close(dev)

Or on Python 3 you can use brother_ql's more high-level variants:

from brother_ql.backends.linux_kernel import BrotherQLBackendLinuxKernel as BrotherQLBackend
printer = BrotherQLBackend("/dev/usb/lp0")
printer.write(qlr.data)

Unfortunately the API is not yet documented. It was also changing a lot until now. The above should, however, be quite stable.