Only package the main source for PyPI

[wnienhaus]

This PR changes MANIFEST.in to exclude everything other than the main source of py-esp32-ulp, such as documentation and tests.

The approach used here is to exclude all files from the root (since the main source lives in esp32_ulp/) and also exclude all other directories by name. (i.e. include all, and then remove most things)

Semantically, I would have wanted to express the opposite: "exclude all, and only include esp32_ulp/". However, this also ended up excluding metadata files that setuptools put in the archive. I could include them again explicitly, but I think this could cause unexpected (hard-to-debug) behaviour in the future, if for example a future version of setuptools added more metadata files, or changed the name of this metadata file. It feels like something that could easily go by unnoticed.

In contrast, if a future change in py-esp32-ulp added a new directory of file, it would be quite noticeable (and understandable) if those files ended up in the package, because MAINFEST.in was not updated to specifically exclude them.

This is why I chose the approach I did.

Footnote

With the opposite approach, MANIFEST.in would have looked like this:

exclude *
prune *
include esp32_ulp/*.py
include micropython_py_esp32_ulp.egg-info/PKG-INFO

(notice having the specifically also include the PKG-INFO file)

Maybe there are other / cleaner ways of achieving the "only package esp32_ulp/*.py" intention?

[ThomasWaldmann]

what does this do to the setup.py?

[wnienhaus]

That rules does exclude setup.py, but in the upip format, setup.py is not included in the package anyway. The MicroPython documentation writes this:

Besides the small compression dictionary size, MicroPython distribution packages also have other optimizations, like removing any files from the archive which aren’t used by the installation process. In particular, upip package manager doesn’t execute setup.py during installation (see below), and thus that file is not included in the archive.

The exclusion happens in sdist_upip.py with this FILTERS rule: https://github.com/ThomasWaldmann/py-esp32-ulp/blob/master/sdist_upip.py#L48 (each tuple is an "(include, exclude)" pattern).

I could perhaps add a comment into the MANIFEST.in file to make this conscious choice (that exclude all is ok to exclude setup.py) clear? Or maybe I should rather change to excluding files one-by-one rather than using such a broad wildcard (for the same reason I defined above, why I exclude directories one-by-one)?

[ThomasWaldmann]

ah, sorry, i did not know that the setup.py isn't used at all.

guess we can keep it as is for now and if we ever need to add files from root, we can still remove the wildcard.