MLPY/Lib/site-packages/cattrs-1.5.0.dist-info/METADATA

Metadata-Version: 2.1
Name: cattrs
Version: 1.5.0
Summary: Composable complex class support for attrs and dataclasses.
Home-page: https://github.com/Tinche/cattrs
Author: Tin Tvrtković
Author-email: tinchester@gmail.com
License: MIT license
Keywords: cattrs
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Natural Language :: English
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Requires-Python: ~=3.7
Requires-Dist: attrs (>=20.1.0)
Provides-Extra: dev
Requires-Dist: bumpversion ; extra == 'dev'
Requires-Dist: wheel ; extra == 'dev'
Requires-Dist: watchdog ; extra == 'dev'
Requires-Dist: flake8 ; extra == 'dev'
Requires-Dist: tox ; extra == 'dev'
Requires-Dist: coverage ; extra == 'dev'
Requires-Dist: Sphinx ; extra == 'dev'
Requires-Dist: pytest ; extra == 'dev'
Requires-Dist: pytest-benchmark ; extra == 'dev'
Requires-Dist: hypothesis ; extra == 'dev'
Requires-Dist: pendulum ; extra == 'dev'
Requires-Dist: isort ; extra == 'dev'
Requires-Dist: black ; extra == 'dev'
Requires-Dist: immutables ; extra == 'dev'

======
cattrs
======


.. image:: https://img.shields.io/pypi/v/cattrs.svg
        :target: https://pypi.python.org/pypi/cattrs

.. image:: https://github.com/Tinche/cattrs/workflows/CI/badge.svg
        :target: https://github.com/Tinche/cattrs/actions?workflow=CI

.. image:: https://readthedocs.org/projects/cattrs/badge/?version=latest
        :target: https://cattrs.readthedocs.io/en/latest/?badge=latest
        :alt: Documentation Status

.. image:: https://img.shields.io/pypi/pyversions/cattrs.svg
        :target: https://github.com/Tinche/cattrs
        :alt: Supported Python versions

.. image:: https://codecov.io/gh/Tinche/cattrs/branch/master/graph/badge.svg
        :target: https://codecov.io/gh/Tinche/cattrs

.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
    :target: https://github.com/ambv/black


----

``cattrs`` is an open source Python library for structuring and unstructuring
data. ``cattrs`` works best with ``attrs`` classes, dataclasses and the usual
Python collections, but other kinds of classes are supported by manually
registering converters.

Python has a rich set of powerful, easy to use, built-in data types like
dictionaries, lists and tuples. These data types are also the lingua franca
of most data serialization libraries, for formats like json, msgpack, yaml or
toml.

Data types like this, and mappings like ``dict`` s in particular, represent
unstructured data. Your data is, in all likelihood, structured: not all
combinations of field names are values are valid inputs to your programs. In
Python, structured data is better represented with classes and enumerations.
``attrs`` is an excellent library for declaratively describing the structure of
your data, and validating it.

When you're handed unstructured data (by your network, file system, database...),
``cattrs`` helps to convert this data into structured data. When you have to
convert your structured data into data types other libraries can handle,
``cattrs`` turns your classes and enumerations into dictionaries, integers and
strings.

Here's a simple taste. The list containing a float, an int and a string
gets converted into a tuple of three ints.

.. code-block:: pycon

    >>> import cattr
    >>>
    >>> cattr.structure([1.0, 2, "3"], tuple[int, int, int])
    (1, 2, 3)

``cattrs`` works well with ``attrs`` classes out of the box.

.. code-block:: pycon

    >>> import attr, cattr
    >>>
    >>> @attr.frozen  # It works with normal classes too.
    ... class C:
    ...     a = attr.ib()
    ...     b = attr.ib()
    ...
    >>> instance = C(1, 'a')
    >>> cattr.unstructure(instance)
    {'a': 1, 'b': 'a'}
    >>> cattr.structure({'a': 1, 'b': 'a'}, C)
    C(a=1, b='a')

Here's a much more complex example, involving ``attrs`` classes with type
metadata.

.. code-block:: pycon

    >>> from enum import unique, Enum
    >>> from typing import Optional, Sequence, Union
    >>> from cattr import structure, unstructure
    >>> import attr
    >>>
    >>> @unique
    ... class CatBreed(Enum):
    ...     SIAMESE = "siamese"
    ...     MAINE_COON = "maine_coon"
    ...     SACRED_BIRMAN = "birman"
    ...
    >>> @attr.define
    ... class Cat:
    ...     breed: CatBreed
    ...     names: Sequence[str]
    ...
    >>> @attr.define
    ... class DogMicrochip:
    ...     chip_id = attr.ib()
    ...     time_chipped: float = attr.ib()
    ...
    >>> @attr.define
    ... class Dog:
    ...     cuteness: int
    ...     chip: Optional[DogMicrochip]
    ...
    >>> p = unstructure([Dog(cuteness=1, chip=DogMicrochip(chip_id=1, time_chipped=10.0)),
    ...                  Cat(breed=CatBreed.MAINE_COON, names=('Fluffly', 'Fluffer'))])
    ...
    >>> print(p)
    [{'cuteness': 1, 'chip': {'chip_id': 1, 'time_chipped': 10.0}}, {'breed': 'maine_coon', 'names': ('Fluffly', 'Fluffer')}]
    >>> print(structure(p, list[Union[Dog, Cat]]))
    [Dog(cuteness=1, chip=DogMicrochip(chip_id=1, time_chipped=10.0)), Cat(breed=<CatBreed.MAINE_COON: 'maine_coon'>, names=['Fluffly', 'Fluffer'])]

Consider unstructured data a low-level representation that needs to be converted
to structured data to be handled, and use ``structure``. When you're done,
``unstructure`` the data to its unstructured form and pass it along to another
library or module. Use `attrs type metadata <http://attrs.readthedocs.io/en/stable/examples.html#types>`_
to add type metadata to attributes, so ``cattrs`` will know how to structure and
destructure them.

* Free software: MIT license
* Documentation: https://cattrs.readthedocs.io.
* Python versions supported: 3.7 and up. (Older Python versions, like 2.7, 3.5 and 3.6 are supported by older versions; see the changelog.)


Features
--------

* Converts structured data into unstructured data, recursively:

  * ``attrs`` classes and dataclasses are converted into dictionaries in a way similar to ``attr.asdict``, or into tuples in a way similar to ``attr.astuple``.
  * Enumeration instances are converted to their values.
  * Other types are let through without conversion. This includes types such as
    integers, dictionaries, lists and instances of non-``attrs`` classes.
  * Custom converters for any type can be registered using ``register_unstructure_hook``.

* Converts unstructured data into structured data, recursively, according to
  your specification given as a type. The following types are supported:

  * ``typing.Optional[T]``.
  * ``typing.List[T]``, ``typing.MutableSequence[T]``, ``typing.Sequence[T]`` (converts to a list).
  * ``typing.Tuple`` (both variants, ``Tuple[T, ...]`` and ``Tuple[X, Y, Z]``).
  * ``typing.MutableSet[T]``, ``typing.Set[T]`` (converts to a set).
  * ``typing.FrozenSet[T]`` (converts to a frozenset).
  * ``typing.Dict[K, V]``, ``typing.MutableMapping[K, V]``, ``typing.Mapping[K, V]`` (converts to a dict).
  * ``attrs`` classes with simple attributes and the usual ``__init__``.

    * Simple attributes are attributes that can be assigned unstructured data,
      like numbers, strings, and collections of unstructured data.

  * All `attrs` classes and dataclasses with the usual ``__init__``, if their complex attributes have type metadata.
  * ``typing.Union`` s of supported ``attrs`` classes, given that all of the classes have a unique field.
  * ``typing.Union`` s of anything, given that you provide a disambiguation function for it.
  * Custom converters for any type can be registered using ``register_structure_hook``.

Credits
-------

Major credits to Hynek Schlawack for creating attrs_ and its predecessor,
characteristic_.

``cattrs`` is tested with Hypothesis_, by David R. MacIver.

``cattrs`` is benchmarked using perf_ and pytest-benchmark_.

This package was created with Cookiecutter_ and the `audreyr/cookiecutter-pypackage`_ project template.

.. _attrs: https://github.com/hynek/attrs
.. _characteristic: https://github.com/hynek/characteristic
.. _Hypothesis: http://hypothesis.readthedocs.io/en/latest/
.. _perf: https://github.com/haypo/perf
.. _pytest-benchmark: https://pytest-benchmark.readthedocs.io/en/latest/index.html
.. _Cookiecutter: https://github.com/audreyr/cookiecutter
.. _`audreyr/cookiecutter-pypackage`: https://github.com/audreyr/cookiecutter-pypackage



=======
History
=======

1.5.0 (2021-04-15)
------------------
* Fix an issue with ``GenConverter`` unstructuring ``attrs`` classes and dataclasses with generic fields.
  (`#65 <https://github.com/Tinche/cattrs/issues/65>`_)
* ``GenConverter`` has support for easy overriding of collection unstructuring types (for example, unstructure all sets to lists) through its ``unstruct_collection_overrides`` argument.
  (`#137 <https://github.com/Tinche/cattrs/pull/137>`_)
* Unstructuring mappings with ``GenConverter`` is significantly faster.
* ``GenConverter`` supports strict handling of unexpected dictionary keys through its ``forbid_extra_keys`` argument.
  (`#142 <https://github.com/Tinche/cattrs/pull/142>`_)

1.4.0 (2021-03-21)
------------------
* Fix an issue with ``GenConverter`` un/structuring hooks when a function hook is registered after the converter has already been used.
* Add support for ``collections.abc.{Sequence, MutableSequence, Set, MutableSet}``. These should be used on 3.9+ instead of their ``typing`` alternatives, which are deprecated.
  (`#128 <https://github.com/Tinche/cattrs/issues/128>`_)
* The ``GenConverter`` will unstructure iterables (``list[T]``, ``tuple[T, ...]``, ``set[T]``) using their type argument instead of the runtime class if its elements, if possible. These unstructuring operations are up to 40% faster.
  (`#129 <https://github.com/Tinche/cattrs/issues/129>`_)
* Flesh out ``Converter`` and ``GenConverter`` initializer type annotations.
  (`#131 <https://github.com/Tinche/cattrs/issues/131>`_)
* Add support for ``typing.Annotated`` on Python 3.9+. ``cattrs`` will use the first annotation present. ``cattrs`` specific annotations may be added in the future.
  (`#127 <https://github.com/Tinche/cattrs/issues/127>`_)
* Add support for dataclasses.
  (`#43 <https://github.com/Tinche/cattrs/issues/43>`_)

1.3.0 (2021-02-25)
------------------
* ``cattrs`` now has a benchmark suite to help make and keep cattrs the fastest it can be. The instructions on using it can be found under the `Benchmarking <https://cattrs.readthedocs.io/en/latest/benchmarking.html>` section in the docs.
  (`#123 <https://github.com/Tinche/cattrs/pull/123>`_)
* Fix an issue unstructuring tuples of non-primitives.
  (`#125 <https://github.com/Tinche/cattrs/issues/125>`_)
* ``cattrs`` now calls ``attr.resolve_types`` on ``attrs`` classes when registering un/structuring hooks.
* ``GenConverter`` structuring and unstructuring of ``attrs`` classes is significantly faster.

1.2.0 (2021-01-31)
------------------
* ``converter.unstructure`` now supports an optional parameter, `unstructure_as`, which can be used to unstructure something as a different type. Useful for unions.
* Improve support for union un/structuring hooks. Flesh out docs for advanced union handling.
  (`#115 <https://github.com/Tinche/cattrs/pull/115>`_)
* Fix `GenConverter` behavior with inheritance hierarchies of `attrs` classes.
  (`#117 <https://github.com/Tinche/cattrs/pull/117>`_) (`#116 <https://github.com/Tinche/cattrs/issues/116>`_)
* Refactor `GenConverter.un/structure_attrs_fromdict` into `GenConverter.gen_un/structure_attrs_fromdict` to allow calling back to `Converter.un/structure_attrs_fromdict` without sideeffects.
  (`#118 <https://github.com/Tinche/cattrs/issues/118>`_)

1.1.2 (2020-11-29)
------------------
* The default disambiguator will not consider non-required fields any more.
  (`#108 <https://github.com/Tinche/cattrs/pull/108>`_)
* Fix a couple type annotations.
  (`#107 <https://github.com/Tinche/cattrs/pull/107>`_) (`#105 <https://github.com/Tinche/cattrs/issues/105>`_)
* Fix a `GenConverter` unstructuring issue and tests.

1.1.1 (2020-10-30)
------------------
* Add metadata for supported Python versions.
  (`#103 <https://github.com/Tinche/cattrs/pull/103>`_)

1.1.0 (2020-10-29)
------------------
* Python 2, 3.5 and 3.6 support removal. If you need it, use a version below 1.1.0.
* Python 3.9 support, including support for built-in generic types (``list[int]`` vs ``typing.List[int]``).
* ``cattrs`` now includes functions to generate specialized structuring and unstructuring hooks. Specialized hooks are faster and support overrides (``omit_if_default`` and ``rename``). See the ``cattr.gen`` module.
* ``cattrs`` now includes a converter variant, ``cattr.GenConverter``, that automatically generates specialized hooks for attrs classes. This converter will become the default in the future.
* Generating specialized structuring hooks now invokes `attr.resolve_types <https://www.attrs.org/en/stable/api.html#attr.resolve_types>`_ on a class if the class makes use of the new PEP 563 annotations.
* ``cattrs`` now depends on ``attrs`` >= 20.1.0, because of ``attr.resolve_types``.
* Specialized hooks now support generic classes. The default converter will generate and use a specialized hook upon encountering a generic class.

1.0.0 (2019-12-27)
------------------
* ``attrs`` classes with private attributes can now be structured by default.
* Structuring from dictionaries is now more lenient: extra keys are ignored.
* ``cattrs`` has improved type annotations for use with Mypy.
* Unstructuring sets and frozensets now works properly.

0.9.1 (2019-10-26)
------------------
* Python 3.8 support.

0.9.0 (2018-07-22)
------------------
* Python 3.7 support.

0.8.1 (2018-06-19)
------------------
* The disambiguation function generator now supports unions of ``attrs`` classes and NoneType.

0.8.0 (2018-04-14)
------------------
* Distribution fix.

0.7.0 (2018-04-12)
------------------
* Removed the undocumented ``Converter.unstruct_strat`` property setter.
* | Removed the ability to set the ``Converter.structure_attrs`` instance field.
  | As an alternative, create a new ``Converter``::
  |
  | .. code-block:: python
  |
  |  >>> converter = cattr.Converter(unstruct_strat=cattr.UnstructureStrategy.AS_TUPLE)
* Some micro-optimizations were applied; a ``structure(unstructure(obj))`` roundtrip
  is now up to 2 times faster.

0.6.0 (2017-12-25)
------------------
* Packaging fixes.
  (`#17 <https://github.com/Tinche/cattrs/pull/17>`_)

0.5.0 (2017-12-11)
------------------
* structure/unstructure now supports using functions as well as classes for deciding the appropriate function.
* added `Converter.register_structure_hook_func`, to register a function instead of a class for determining handler func.
* added `Converter.register_unstructure_hook_func`, to register a function instead of a class for determining handler func.
* vendored typing is no longer needed, nor provided.
* Attributes with default values can now be structured if they are missing in the input.
  (`#15 <https://github.com/Tinche/cattrs/pull/15>`_)
* | `Optional` attributes can no longer be structured if they are missing in the input.
  | In other words, this no longer works:
  |
  | .. code-block:: python
  |
  |    @attr.s
  |    class A:
  |        a: Optional[int] = attr.ib()
  |
  |    >>> cattr.structure({}, A)
  |
* ``cattr.typed`` removed since the functionality is now present in ``attrs`` itself.
  Replace instances of ``cattr.typed(type)`` with ``attr.ib(type=type)``.

0.4.0 (2017-07-17)
------------------
* `Converter.loads` is now `Converter.structure`, and `Converter.dumps` is now `Converter.unstructure`.
* Python 2.7 is supported.
* Moved ``cattr.typing`` to ``cattr.vendor.typing`` to support different vendored versions of typing.py for Python 2 and Python 3.
* Type metadata can be added to ``attrs`` classes using ``cattr.typed``.


0.3.0 (2017-03-18)
------------------
* Python 3.4 is no longer supported.
* Introduced ``cattr.typing`` for use with Python versions 3.5.2 and 3.6.0.
* Minor changes to work with newer versions of ``typing``.

  * Bare Optionals are not supported any more (use ``Optional[Any]``).

* Attempting to load unrecognized classes will result in a ValueError, and a helpful message to register a loads hook.
* Loading ``attrs`` classes is now documented.
* The global converter is now documented.
* ``cattr.loads_attrs_fromtuple`` and ``cattr.loads_attrs_fromdict`` are now exposed.


0.2.0 (2016-10-02)
------------------
* Tests and documentation.

0.1.0 (2016-08-13)
------------------
* First release on PyPI.