README.python3

DeprecationWarning: invalid escape sequence \s
in classes werden alle regexp als r"raw string" geschrieben


Legacy Python (<3.8) support
============================

The coshsh core sources target Python 3.12 and use syntax that does not even
compile on Python 3.6/3.7 (`from __future__ import annotations`, PEP 585/604
annotations, `typing.Protocol`). To run the *unmodified* sources on those old
interpreters (CentOS 7 / RHEL 7-era distros, OMD packaging) there is an additive,
version-gated compatibility layer:

    coshsh_pycompat.py    (top-level module, sibling of the coshsh/ package)

It installs an import hook, scoped to the coshsh.* namespace, that strips
annotations from the coshsh source AST before compilation, plus small no-op
shims for typing.Protocol and subprocess.run(capture_output=). On Python >= 3.8
importing it is completely inert (a version gate short-circuits) and nothing is
installed. See specs/006-legacy-python-compat/ for the full design.

Supported legacy run path = FROM THE SOURCE TREE (not pip):

    # from the package root, on Python 3.6/3.7:
    TMPDIR=/tmp pytest-3 -p no:cacheprovider -q       # run the tests
    bin/coshsh-cook --cookbook <file>                 # run the generator

The bin scripts and tests/conftest.py activate the layer automatically (gated on
sys.version_info < (3, 8)). `pip install` on <3.8 is intentionally blocked:
setup.py keeps `python_requires='>=3.8'`, so the compat layer is deliberately a
source-tree module discovered via sys.path, NOT a py_modules install entry.

CI exercises both paths (.github/workflows/python-app.yml): the `build` job runs
3.8-3.13 (layer inert, tests/test_pycompat.py skipped) and the `legacy` job runs
3.6/3.7 inside python:<ver>-slim-bullseye containers (layer active,
tests/test_pycompat.py executes).