[Distutils] Entry points: specifying and caching

[Paul Moore]

On 18 October 2017 at 19:42, Thomas Kluyver <thomas at kluyver.me.uk> wrote:
> On Wed, Oct 18, 2017, at 05:59 PM, Paul Moore wrote:
>> > I've always used the setuptools documentation as a reference. Are you
>> > suggesting moving that information to a different location to
>> > allow/encourage other tools to implement it as a standard?
>>
>> I've never used entry points myself (other than the console script
>> entry points supported by packaging) but a quick Google search found
>> http://setuptools.readthedocs.io/en/latest/setuptools.html#dynamic-discovery-of-services-and-plugins
>> as the only obvious candidate for documentation (and a bit later I
>> thought of looking under pkg_resources and found
>> http://setuptools.readthedocs.io/en/latest/pkg_resources.html#entry-points).
>> This doesn't really say how the entry point data is stored in the
>> project metadata, so it's not clear how I'd read that data in my own
>> code (the answer is of course to use pkg_resources, but the point of
>> documenting it as a standard is to allow alternative implementations).
>
> I have in fact made an alternative implementation (PyPI package
> entrypoints) by 'reverse engineering' the format. A simple text-based
> format doesn't really justify the term 'reverse engineering', but for
> instance it wasn't obvious to me that the names were case sensitive,
> whereas Python's standard config parser treats keys as case-insensitive.
>
> Daniel:
>> http://setuptools.readthedocs.io/en/latest/formats.html?highlight=entry_points.txt#entry-points-txt-entry-point-plugin-metadata
>
> Thanks, this link is closer than any I found to a specification. There
> are docs on how to create entry points in setup.py and how to use them
> with pkg_resources, but that's the only bit I've seen that describes the
> interchange file format.

Agreed, I hadn't found that, either.

> I think we can probably expand on it a bit, though! I'll try to put
> together something for packaging.python.org.

One thing that immediately strikes me is that the encoding of the file
is unspecified...
Paul