[Python-Dev] #12982: Should -O be required to read .pyo files? (original) (raw)

Brett Cannon brett at python.org
Thu Jun 14 16:58:55 CEST 2012

On Wed, Jun 13, 2012 at 10:47 PM, R. David Murray <rdmurray at bitdance.com>wrote:

On Thu, 14 Jun 2012 11:48:08 +1000, Nick Coghlan <ncoghlan at gmail.com> wrote: > On Thu, Jun 14, 2012 at 6:06 AM, Terry Reedy <tjreedy at udel.edu> wrote: > > On 6/13/2012 2:46 PM, Antoine Pitrou wrote: > > > >> Not only docstrings, but also asserts. I think running a pyo without -O > >> would be a bug. > > > > That cat is already out of the bag ;-) > > People are doing that now by renaming x.pyo to x.pyc. > > Brett claims that it is also easy to do in 3.3 with a custom importer. > > Right, but by resorting to either of those approaches, people are > clearly doing something that isn't formally supported by the core. > Yes, you can do it, and most of the time it will work out OK, but any > weird glitches that result are officially not our problem. > > The main reason this matters is that the "debug" flag is > supposed to be process global - if you check it in one place, the

OK, the above are the two concrete reasons I have heard in this thread for continuing the current behavior: 1) we do not wish to support running from .pyo files without -O being on, even if it currently happens to work 2) the debug setting is supposed to be process-global Both of these are good reasons. IMO the issue should be closed with a documentation fix, which could optionally include either or both of the above motivations.

Just for completeness, there is a third reason:

  1. Would lead to an extra stat call per module when doing sourceless loads.

While minor, it could add up if you ship only .pyo files but never run with -O. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20120614/7411e790/attachment.html>

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