[Python-Dev] PEP 441 - Improving Python ZIP Application Support

[Nick Coghlan]

On 15 February 2015 at 23:21, Paul Moore <p.f.moore at gmail.com> wrote:
> On 15 February 2015 at 08:59, Nick Coghlan <ncoghlan at gmail.com> wrote:
>> The other option would to cut PEP 441 way back to *just* be about
>> standardising and registering the file associations, and recommending
>> the use of pip to obtain the build machinery with (whether pyzaa,
>> pyzzer or Twitter's more comprehensive pex). It would be a short PEP,
>> but potentially still worth it for the improved visibility of the
>> decision when folks are trying to figure out what "pyz" and "pyzw"
>> files are later.
>
> Ok, thinking about this a little more.
>
> Getting the extension support is the key thing on Windows - at the
> moment, people are faced with adding their own file associations or
> putting binary data in a .py file, neither of which is a nice choice.
> Tooling is important, though - sure, you can zip the data up and put a
> header on, but it's fiddly.
>
> Which brings us full circle. A simple module, executable as "python -m
> zipapp" (see below re name) which exports a single function, pack()
> that creates the archive. If we want to provide a script to wrap the
> module, like pyvenv.py does for venv, I've no objection to that -
> presumably it would go in Tools/Scripts? If people (like me) want to
> experiment with a more programmatic API for building pyz files, they
> can do so on PyPI, and if such a thing becomes sufficiently mature we
> can look then at proposing it for inclusion in the stdlib, as an
> extension to the zipapp module.
>
> Regarding naming, I'm happy to go with zipapp if it's your preference.
> Presumably the wrapper in Tools/Scripts would be pyzipapp.py?

Or we just skip the wrapper and make "python -m zipapp" the
recommended invocation style. Adding a wrapper later is fairly easy,
but removing it would be difficult.

>
> So the usage would be something like
>
>     python -m zipapp [options] dir_to_zip
>
> Options:
>     -p <interpreter>    The interpreter to use on the shebang line
> (defaulting to /usr/bin/env python)
>     -o archive_name     The name of the output file (defaulting to the
> source directory name with a .pyz extension)
>                         If the argument has no extension, add '.pyz'
>     -m module:function  The entry point to call (written to __main__.py)
>                         Using this is an error if there is a
> __main__.py, and mandatory if there isn't
>
> If you want anything more complex, it's easy enough to write your own
> script based on zipfile, or use one of the modules on PyPI.
>
> Does this sound reasonable? If it's OK, I'll go ahead and prepare an
> update to the PEP and an implementation. (Steve, looks like I may be
> learning how to maintain the wix files after all - wish me luck :-))
> If I hear no objections in the next couple of days, I'll assume
> everyone's OK with it and I'll prepare a PEP update and a patch.

Sounds good to me.

Daniel, do you mind if Paul becomes a co-author on PEP 441 and updates
it as described? It seems a bit tidier than allocating a new PEP
number and rejecting PEP 441, when the revised proposal is essentially
just a simplified and renamed version of your original idea.

Cheers,
Nick.

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