Building a package with generated Python files - setuptools

Question

Problem statement
When building a Python package I want the build tool to automatically execute the steps to generate the necessary Python files and include them in the package.
Here are some details about the project:
the project repository contains only the hand-written Python and YAML files
to have a fully functional package the YAML files must be compiled into Python scripts
once the Python files are generated from YAMLs, the program needed to compile them is no longer necessary (build dependency).
the hand-written and generated Python files are then packaged together.
The package would then be uploaded to PyPI.
I want to achieve the following:
When the user installs the package from PyPI, all necessary files required for the package to function are included and it is not necessary to perform any compile steps
When the user checks-out the repository and builds the package with python -m build . --wheel, the YAML files are automatically compiled into Python and included in the package. Compiler is required.
When the user checks-out the repository and installs the package from source, the YAML files are automatically compiled into Python and installed. Compiler is required.
(nice to have) When the user checks-out the repository and installs in editable mode, the YAML files are compiled into Python. The user is free to make modifications to both generated and hand-written Python files. Compiler is required.
I have a repository with the following layout:
├── <project>
│ └── <project>
│ ├── __init__.py
│ ├── hand_written.py
│ └── specs
│ └── file.ksc (YAML file)
└── pyproject.toml
And the functional package should look something like this
├── <project>
│ └── <project>
│ ├── __init__.py
│ ├── hand_written.py
│ └── generated
│ └── file.py
├── pyproject.toml
└── <other package metadata>
How can I achieve those goals?
What I have so far
As I am very fresh to Python packaging, I have been struggling to understand the relations between the pyproject.toml, setup.cfg and setup.py and how I can use them to achieve the goals I have outlined above. So far I have a pyproject.toml with the following content:
[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"
[project]
name = "<package>"
version = "xyz"
description = "<description>"
authors = [ <authors> ]
dependencies = [
"kaitaistruct",
]
From reading the setuptools documentation, I understand that there are the build commands, such as:
build_py -- simply copies Python files into the package (no compiling; works differently in editable mode)
build_ext -- builds C/C++ modules (not relevant here?)
I suppose adding the compile steps for the YAML files will involve writing a setup.py file and overwriting a command, but I don't know if this is the right approach, whether it will even work, or if there are better methods, such as using a different build backend.
Alternative approaches
A possible alternative approach would be to manually compile the YAML files prior to starting the installation or build of the package.