compreq

A library for dynamically computing Python requirements, to keep them up-to-date.

Concepts

This library relies heavily on packaging, and you should understand that first.

The base types are the Version, Specifier, SpecifierSet and Requirement in packaging and Release and ReleaseSet added by this library.

For all of the base types this library adds lazy versions - which both allows reuse, but also allows some values to be fetched from the context, instead of specified explicitly.

To resolve a lazy object into a concrete value use a CompReq.resolve_... method.

Finally this library adds wrappers around pyproject.toml and requirements.txt files, for getting and setting the requirments in them.

Example:

import compreq as cr

with cr.PoetryPyprojectFile.open() as pyproject:
    prev_python_specifier = cr.get_bounds(
        pyproject.get_requirements()["python"].specifier
    ).lower_specifier_set()
    comp_req = cr.CompReq(python_specifier=prev_python_specifier)

    default_range = cr.version(
        ">=",
        cr.floor_ver(
            cr.REL_MINOR,
            cr.minimum_ver(
                cr.max_ver(cr.min_age(years=1)),
                cr.min_ver(cr.count(cr.MINOR, 3)),
            ),
        ),
    ) & cr.version("<", cr.ceil_ver(cr.REL_MAJOR, cr.max_ver()))

    dev_range = cr.version(">=", cr.floor_ver(cr.REL_MINOR, cr.max_ver())) & cr.version(
        "<", cr.ceil_ver(cr.REL_MINOR, cr.max_ver())
    )

    pyproject.set_requirements(
        comp_req,
        [
            cr.pkg("beautifulsoup4") & default_range,
            cr.pkg("packaging") & default_range,
            cr.pkg("pip") & default_range,
            cr.pkg("python") & default_range,
            cr.pkg("python-dateutil") & default_range,
            cr.pkg("requests") & default_range,
            cr.pkg("tomlkit") & default_range,
            cr.pkg("typing-extensions") & default_range,
        ],
    )
    pyproject.set_requirements(
        comp_req,
        [
            cr.pkg("black") & dev_range,
            cr.pkg("isort") & dev_range,
            cr.pkg("mypy") & dev_range,
            cr.pkg("pylint") & dev_range,
            cr.pkg("pytest") & dev_range,
            cr.pkg("taskipy") & dev_range,
            cr.pkg("types-beautifulsoup4") & default_range,
            cr.pkg("types-python-dateutil") & default_range,
            cr.pkg("types-requests") & default_range,
        ],
        "dev",
    )

Or see requirements.py.

References:

https://peps.python.org/pep-0440/ https://packaging.pypa.io/en/stable