[Python-Dev] Is there a reference manual for Python bytecode?

[Nick Coghlan]

On 27 December 2015 at 12:23, Guido van Rossum <guido at python.org> wrote:
> On Sat, Dec 26, 2015 at 6:06 PM, Brett Cannon <brett at python.org> wrote:
>>
>> Ned also neglected to mention his byterun project which is a pure Python
>> implementation of the CPython eval loop: https://github.com/nedbat/byterun
>
> From the commit log it looks like it's a co-production between Ned and
> Allison Kaptur (who gave the talk I mentioned).

It occurred to me that "byterun" would make a good see-also link from
the dis module docs, and looking into that idea brought me to this
article Allison wrote about it for the "500 lines" project:
http://aosabook.org/en/500L/a-python-interpreter-written-in-python.html

For a detailed semantic reference, byterun's eval loop is likely one
of the most readable sources of information:
https://github.com/nedbat/byterun/blob/master/byterun/pyvm2.py

In terms of formal documentation, the main problem with providing
reference bytecode tables is keeping them up to date as the eval loop
changes. However, it would theoretically be possible to create a
custom Sphinx directive that uses the dis module to generate the
tables automatically during the docs build process, rather than
maintaining them by hand - something like that could be experimented
with outside CPython, and potentially incorporated into the dis module
docs if folks are able to figure out something that works well.

Regards,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia