How was data4mask.py created?

[s-w-s]

In the file data4mask.py the header says that it was produced by isbntools-dev in May 2021.
Clearly, the source code referenced a range file from isbn international and, possibly, files from national or language group authorities. But looking through the github repository for isbntools, I have not been able to find the source code that produced data4mask.py. Is it available? If so, can you point me to it? Thanks in advance for any help you can offer.

[xlcnd]

Hi!
That file was produced using isbntools-dev which is not public available (for now, it uses proprietary tools that are not easy to replace).

[s-w-s]

Does isbntools-dev also access the national or language group files, e.g. from Bowker, that detail assignments to publishers?

[xlcnd]

Just uses ISBN Ranges.

[s-w-s]

Thank you.

[xlcnd]

If you want python code that produce those files, see pr #120.