Question on importing a GPL'ed Python library in commercial code

Question

We're evaluating a couple of Python libraries for Graph manipulation. We tried 'networkx' (http://networkx.lanl.gov/) and 'igraph' (http://igraph.sourceforge.net/).

While both are excellent modules, igraph is faster due to its nature - it's a Python wrapper over libigraph - a blistering fast graph C library (uses LAPACK etc).

Now, the igraph library is GPL licensed. My question is: Can I import igraph and use it in my commercial Python script?

(This is a general question, not just limited to igraph. Apologies if the answer is obvious - I'm a license-newb!)

Thanks, Raj

EDIT: More specifically, does simply importing a GPL Python module make my commercial code liable to be released to the public?

Answer 1

IANAL, etc etc, but:

The Free Software Foundation has consistently claimed that software linked to a library covered by GPL is a derived work, and thus needs to be covered by GPL itself (indeed, that's the main difference of the LGPL license). I don't know how the situation stands in court precedents in various jurisdiction, &c, but if you don't want to risk having to litigate on the issue [which would no doubt bring costs and bad PR even if it were to ultimately succeed], it may be more prudent to avoid linking to GPL libraries (including dynamic linking) if you don't want to distribute the sources to your code.