[PyQt] A nasty licencing question

Sampsa Riikonen sampsa.riikonen at iki.fi
Mon Jul 30 14:19:54 BST 2018

On 30.07.2018 13:47, David Boddie wrote:
> On Mon Jul 30 10:23:50 BST 2018, Sampsa Riikonen wrote:
>> On 30.07.2018 12:16, David Boddie wrote:
>>> How does apply to the scripts you were talking about? Sure, the combined
>>> work is now licensed under the GPL but the original scripts can still be
>>> obtained from outside the combined work and are still MIT licensed.
> I was being a bit careless with words. I meant "snippets" rather than
> "scripts", but your questions below are still valid. In my mind they are
> different things, but that's not important here. :-)
>> What do you mean David..?
>> Do you mean if you remove "from PyQt5 import .." then that's "outside
>> combined work" and thus is not anymore GPL licensed?
> No, if you obtain something licensed under the GPL then changing the module
> dependencies isn't going to change its license.

Hi David,

This is exactly what I was talking about.

So, if at a certain moment, you don't have the PyQt license and add the
following line into your code:

from PyQt import ...

Then that's it.  Your code will be forever GPL .. it became GPL at the
very moment you distributed it (uploaded to the internet).  You can't
use it anymore in any other context that GPL.  Even removing those
damning lines wont save it.

If the author claims that the module has a MIT (or any other license),
the people using that module must find out if the author had a valid
PyQt license at the moment he distributed it.. otherwise they step on
the license landmine (a nice legal limbo)

However, if you write

# from PyQt import ..  # be aware of the licensing consequences
from PySide2 import ..

Then the licensing landmine doesn't go off, as the first line is a
comment only, not actual code.  Funny world.  :)



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