| Lock Files |
| ========== |
|
|
| .. currentmodule:: packaging.pylock |
|
|
| Parse and validate `pylock.toml files <https://packaging.python.org/en/latest/specifications/pylock-toml/>`_. |
|
|
| Usage |
| |
|
|
| .. code-block:: python |
|
|
| import tomllib |
| from pathlib import Path |
|
|
| from packaging.pylock import Package, PackageWheel, Pylock, is_valid_pylock_path |
| from packaging.utils import NormalizedName |
| from packaging.version import Version |
|
|
| # validate a pylock file name |
| assert is_valid_pylock_path(Path("pylock.example.toml")) |
|
|
| # parse and validate pylock file |
| toml_dict = tomllib.loads(Path("pylock.toml").read_text(encoding="utf-8")) |
| pylock = Pylock.from_dict(toml_dict) |
| # the resulting pylock object is validated against the specification, |
| # else a PylockValidationError is raised |
|
|
| # generate a pylock file |
| pylock = Pylock( |
| lock_version=Version("1.0"), |
| created_by="some_tool", |
| packages=[ |
| Package( |
| name=NormalizedName("example-package"), |
| version=Version("1.0.0"), |
| wheels=[ |
| PackageWheel( |
| url="https://example.com/example_package-1.0.0-py3-none-any.whl", |
| hashes={"sha256": "0fd.."}, |
| ) |
| ], |
| ) |
| ], |
| ) |
| toml_dict = pylock.to_dict() |
| # use a third-party library to serialize to TOML |
|
|
| # you can validate a manually constructed Pylock class |
| pylock.validate() |
|
|
| # select packages to install for the current environment |
| for package, artifact in pylock.select(): |
| print(f"Install {package.name} from {artifact}") |
|
|
| Validation |
| |
|
|
| :meth:`Pylock.from_dict` and :meth:`Pylock.validate` check the structure of |
| the lock file against the specification. Required fields must be present, |
| fields must have the expected types, package and extra names must be |
| normalized, and versions, specifiers and markers must parse. Each package |
| must have exactly one source: distribution files (``sdist`` or ``wheels``), |
| or one of ``vcs``, ``directory`` or ``archive``. Wheel and sdist filenames |
| must be parseable (see :func:`~packaging.utils.parse_wheel_filename` and |
| :func:`~packaging.utils.parse_sdist_filename`) and match the package name |
| and version. |
|
|
| Validation stops at the structure. URL and path fields, including |
| ``packages.index``, are stored as-is. They are not checked to be valid URLs |
| or paths, and relative paths are not resolved against the location of the |
| lock file. A wheel or sdist entry with no ``name`` takes its filename from |
| the last component of its ``path`` or ``url``; nothing else is read from |
| these fields. ``hashes`` tables must be non-empty and their values must be |
| strings, but algorithm names and digest formats are not checked. Nothing is |
| downloaded, so checking hashes and sizes against the actual artifacts is up |
| to the caller. |
|
|
| Reference |
| |
|
|
| .. autofunction:: is_valid_pylock_path |
|
|
| The following frozen keyword-only dataclasses are used to represent the |
| structure of a pylock file. The attributes correspond to the fields in the |
| pylock file specification. |
|
|
| .. autoclass:: Pylock |
| :members: from_dict, to_dict, validate, select |
| :exclude-members: __init__, __new__ |
|
|
| .. class:: Package |
|
|
| .. class:: PackageWheel |
|
|
| .. class:: PackageSdist |
|
|
| .. class:: PackageArchive |
|
|
| .. class:: PackageVcs |
|
|
| .. class:: PackageDirectory |
|
|
| The following exceptions may be raised by this module: |
|
|
| .. autoexception:: PylockValidationError |
| :exclude-members: __init__, __new__ |
|
|
| .. autoexception:: PylockUnsupportedVersionError |
| :exclude-members: __init__, __new__ |
|
|
| .. autoexception:: PylockSelectError |
| :exclude-members: __init__, __new__ |
|
|
