[Python-Dev] Request for Pronouncement: PEP 441 - Improving Python ZIP Application Support

[Daniel Holth]

Sounds reasonable. It could be done by just reading the entire file
contents after the shebang and re-writing them with the necessary
offset all in RAM, truncating the file if necessary, without involving
the zipfile module very much; the shebang could have some amount of
padding by default; the file could just be re-compressed in memory
depending on your appetite for complexity.

On Mon, Feb 23, 2015 at 1:49 PM, Paul Moore <p.f.moore at gmail.com> wrote:
> On 23 February 2015 at 18:40, Brett Cannon <brett at python.org> wrote:
>> Couldn't you just keep it in memory as bytes and then write directly over
>> the file? I realize that's a bit wasteful memory-wise but it is possible.
>> The docs could mention the memory cost is something to watch out for when
>> doing an in-place replacement. Heck the code could even make it an
>> io.BytesIO instance so the rest of the code doesn't have to care about this
>> special case.
>
> I did consider this option, and I still quite like it. In fact,
> originally I wrote the API to *only* be in-place, until I realised
> that wouldn't work for things bigger than memory (but who has a Python
> app that's bigger than RAM?)
>
> I'm happy to modify the API along these lines (details to be thrashed
> out) if people think it's worthwhile.
> Paul