On Thu, Apr 2, 2020 at 7:55 PM Matt Billenstein <matt@vazor.com> wrote:
On Thu, Apr 02, 2020 at 05:17:31PM -0700, Guido van Rossum wrote:
> On Thu, Apr 2, 2020 at 4:20 PM Nathaniel Smith <njs@pobox.com> wrote:
>     If the AST is supposed to be the same, then would it make sense to
>     temporarily – maybe just during the alpha/beta period – always run
>     *both* parsers and confirm that they match?
> That's not a bad idea! https://github.com/we-like-parsers/cpython/issues/33

Even just running it in a dev build against the corpus of the top few
thousand packages on pypi might give enough confidence -- I had a script
to download the top N packages and run some script over the python files
contained therein, but I can't seem to find it atm.

We got that. Check https://github.com/gvanrossum/pegen/tree/master/scripts -- look at download_pypi_packages.py and test_pypi_packages.py.

--Guido van Rossum (python.org/~guido)