[Python-Dev] PEP 397 - Last Comments

[Brian Curtin]

Martin approached me earlier and requested that I act as PEP czar for
397. I haven't been involved in the writing of the PEP and have been
mostly observing from the outside, so I accepted and hope to get this
wrapped up quickly and implemented in time for the beta. The PEP is
pretty complete, but there are a few outstanding issues.

On Mon, Jun 18, 2012 at 1:05 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> "Independent installations will always only overwrite newer versions of the
> launcher with older versions." 'always only' is a bit awkward and the
> sentence looks backwards to me. I would expect only overwriting older
> versions with newer versions.

Agreed, I would expect the same. I would think taking out the word
"only" and then flipping newer and older in the sentence would correct
it.

On Mon, Jun 18, 2012 at 1:05 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> These seem contradictory:
>
> "The 32-bit distribution of Python will not install a 32-bit version of the
> launcher on a 64-bit system."
>
> I presume this mean that it will install the 64-bit version and that there
> will always be only one version of the launcher on the system.
>
> "On 64bit Windows with both 32bit and 64bit implementations of the same
> (major.minor) Python version installed, the 64bit version will always be
> preferred.  This will be true for both 32bit and 64bit implementations of
> the launcher - a 32bit launcher will prefer to execute a 64bit Python
> installation of the specified version if available."
>
> This implies to me that the 32bit installation *will* install a 32bit
> launcher and that there could be both versions of the launcher installed.

I took that as covering an independently-installed launcher.

You could always install your own 32-bit launcher, and it'd prefer to
launch a binary matching the machine type. So yes, there could be
multiple launchers installed for different machine types, and I'm not
sure why we'd want to (or how we could) prevent people from installing
them. You could have a 64-bit launcher available system-wide in your
Windows folder, then you could have a 32-bit launcher running out of
C:\Users\Terry for some purposes.

Martin - is that correct?

===

Outside of Terry's concerns, I find the updated PEP almost ready to go
as-is. Many of the updates were in line with what Martin and I briefly
talked about at PyCon, and I believe some of them came out of previous
PEP discussions on here, so I see nothing unexpected at this point.

My only additional comment would be to have the "Configuration file"
implementation details supplemented with a readable example of where
the py.ini file should be placed. On my machine that is
"C:\Users\brian\AppData\Local", rather than making people have to run
that parameter through the listed function via pywin32.