[Python-Dev] AST optimizer implemented in Python

["Martin v. Löwis"]

>> +1  We should add some form of setastoptimizer API in 3.4.  Please start a
>> PEP for this.  It would be nice to include the ability to properly cache the
>> ast optimizer output so that it does not have to run every time (in pyc
>> files or similar, etc) but can verify that it is the specific ast optimizer
>> that ran on a give existing cached copy.
>
> Once .pyc is created, I do not think that we keep the AST around any
> longer. Otherwise, I wouldn't have to write PyXfuscator.
>
> https://bitbucket.org/namn/pyxfuscator
>
> Or perhaps I am misunderstanding you.

I think you misunderstood. What gps is concerned about (IIUC) that some
people add ast optimizers in some run of Python, but other AST 
optimizers in a different run. Then, if you use a Python byte code
file, you should be able to find out what AST optimizers have been
run to create the pyc file, so you know whether you have to recompile
or not.

Of course, if that is really a desirable feature, you may want multiple
pyc files, per combination of AST optimizers. The __pycache__ directory
would readily support that.

This seems to get complicated quickly, so a PEP is indeed desirable.

Regards,
Martin