[Python-Dev] More optimisation ideas

[Andrew Barnert]

On Friday, February 5, 2016 11:57 AM, Emile van Sebille <emile at fenx.com> wrote:



> Aah, 'must' is less restrictive in this context than I expected. When 
> you combine the two halves the first part might be more accurately 
> phrased as 'The program must make source code available' rather than 
> 'must include' which I understood to mean 'ship with'.

First, step back and think of this in common sense terms: If being open source required any Python installation to have the .py source to the .pyc or .zip files in the stdlib, surely it would also require any Python installation to have the .c source to the interpreter too. But lots of people have Python without having the .c source.

Also, the GPL isn't typical of all open source licenses, it's only typical of _copyleft_ licenses. Permissive licenses, like Python's, are very different. Copyleft licenses are designed to make sure that all derived works are also copylefted; permissive licenses are designed to permit derived works as widely as possible. As the Python license specifically says, "All Python licenses, unlike the GPL, let you distribute a modified version without making your changes open source."

Meanwhile, the fact that someone has decided that the Python license qualifies under the Open Source Definition doesn't mean the OSD is the right way to understand it. Read the license itself, or one of the summaries at opensource.org or fsf.org. (And if you still can't figure something out, and it's important to your work, you almost certainly need to ask a lawyer.) So, if you think the first sentence of section 2 of the OSD contradicts the explanation in the rest of the paragraph--well, even if you're right, that doesn't affect Python's license at all.

Finally, if you want to see what it takes to actually make all the terms unambiguous both to ordinary human beings and to legal codes, see the GPL FAQ sections on their definitions of "propagate" and "convey". It may take you lots of careful reading to understand it, but when you finally do, it's definitely unambiguous.