GPL and Python modules.

[Michael Sparks]

On 25 Oct 2004, Grant Edwards wrote:

> On 2004-10-25, Peter Otten <__peter__ at web.de> wrote:
> > Grant Edwards wrote:
> >
> >> Let's say I use a GPL'd python module (e.g. something installed
> >> in site-packages) in an application.
> >
> > I'd say everything that uses a GPL'd module is derived work
> > and must also be GPL'd. It doesn't matter how you distribute
> > it.
>
> So my application code must be GPL'd even if I never distribute
> the module?  The mere act of inserting the line
>
> "import someGPLdmodule"
>
> Makes my _source_code_ a derived work, and therefore must be
> GPL'd?  That just doesn't sound right.

Depends. If you pull in and use a specific GPL module, then yes, it is
GPL'd. If you don't distribute said GPL module, and you can show
reasonable doubt whether:

   import foo

imports the GPL foo or the non-GPL foo (say 2 files both independently
implemented to a common test suite for a standard), then it's much more
woolley.

After all if "foo" on the target system is from (say) a BSD'd
implementation and your code uses that, then your code isn't GPL
(obviously). If "foo" on the target system is (say) a GPL'd
implementation and your code uses that, then your code does have
to be GPL.

Put another way, if your code is shipped in the py2exe bundle with GPL'd
code and your code will not run without it, then its a derivative work in
the terms of the GPL.

However you can still hit this if the py2exe bundle has to use GPL'd
code even if you don't distribute it - for example if it's the only
implementation that python will bind the names to at run time  because
the only implementation available is GPL.

(These issues are generally why the LGPL was created in the first place if
you're going HUH???!!?!)


Michael.
--
(Not a lawyer, this is not legal advice)