Sybren A. Stüvel 68ac3c03e3 Add-on: compatibility with Python 3.9
Remove some Python 3.10 features to make the add-on compatible with py39.
This is the Python version that's bundled with Blender 2.93 LTS, for which
I got a request to see if it could be supported.

The Blender version still isn't officially supported, but this should make
things at least not immediately fail.
2024-04-24 17:32:01 +02:00
..
2022-03-25 14:10:26 +01:00

Flamenco 3 Blender add-on

Setting up development environment

~/workspace/blender-git/build_linux/bin/3.1/python/bin/python3.9 -m venv --upgrade-deps venv
. ./venv/bin/activate
pip install poetry
poetry install

Generating the OpenAPI client

  1. Make sure Java is installed (so java --version shows something sensible).
  2. In the root directory of the repository, run make generate-py

Type annotations and lazy imports

This add-on tries to only load Python packages from wheel files when necessary. Loading things from wheels is tricky, as they basically pollute the sys.modules dictionary and thus can "leak" to other add-ons. This can cause conflicts when, for example, another add-on is using a different version of the same package.

The result is that sometimes there are some strange hoops to jump through. The most obvious one is for type annotations. This is why you'll see code like:

if TYPE_CHECKING:
    from .bat_interface import _PackThread
else:
    _PackThread = object

This makes it possible to declare a function with def func() -> _PackThread, without having to load bat_interface immediately at import time.