https://github.com/ericvsmith/dataclasses

https://github.com/ericvsmith/dataclasses

Last synced: 8 days ago
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• Host: GitHub
• URL: https://github.com/ericvsmith/dataclasses
• Owner: ericvsmith
• License: apache-2.0
• Created: 2017-05-19T20:46:27.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2024-07-11T16:14:35.000Z (4 months ago)
• Last Synced: 2024-10-29T16:17:31.795Z (15 days ago)
• Language: Python
• Size: 341 KB
• Stars: 584
• Watchers: 12
• Forks: 53
• Open Issues: 8
• Metadata Files:
  • Readme: README.rst
  • License: LICENSE.txt

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README

        
.. image:: https://img.shields.io/pypi/v/dataclasses.svg

   :target: https://pypi.org/project/dataclasses/

Copyright 2017-2022 Eric V. Smith, all rights reserved.

This is an implementation of PEP 557, Data Classes.  It is a backport

for Python 3.6.  Because dataclasses will be included in Python 3.7,

any discussion of dataclass features should occur on the python-dev

mailing list at https://mail.python.org/mailman/listinfo/python-dev.

At this point this repo should only be used for historical purposes

(it's where the original dataclasses discussions took place) and for

discussion of the actual backport to Python 3.6.

See https://www.python.org/dev/peps/pep-0557/ for the details of how

Data Classes work.

A test file can be found at

https://github.com/ericvsmith/dataclasses/blob/master/test/test_dataclasses.py,

or in the sdist file.

Installation

-------------

.. code-block::

  pip install dataclasses

Example Usage

-------------

.. code-block:: python

  from dataclasses import dataclass

  @dataclass

  class InventoryItem:

      name: str

      unit_price: float

      quantity_on_hand: int = 0

      def total_cost(self) -> float:

          return self.unit_price * self.quantity_on_hand

  item = InventoryItem('hammers', 10.49, 12)

  print(item.total_cost())

Some additional tools can be found in dataclass_tools.py, included in

the sdist.

Compatibility

-------------

This backport assumes that dict objects retain their insertion order.

This is true in the language spec for Python 3.7 and greater.  Since

this is a backport to Python 3.6, it raises an interesting question:

does that guarantee apply to 3.6?  For CPython 3.6 it does.  As of the

time of this writing, it's also true for all other Python

implementations that claim to be 3.6 compatible, of which there are

none.  Any new 3.6 implementations are expected to have ordered dicts.

See the analysis at the end of this email:

https://mail.python.org/pipermail/python-dev/2017-December/151325.html

As of version 0.4, this code no longer works with Python 3.7. For 3.7,

use the built-in dataclasses module.

Release History

---------------

+---------+------------+-------------------------------------+

| Version | Date       | Description                         |

+=========+============+=====================================+

| 0.8     | 2020-11-13 | Fix ClassVar in .replace()          |

+---------+------------+-------------------------------------+

| 0.7     | 2019-10-20 | Require python 3.6 only             |

+---------+------------+-------------------------------------+

| 0.6     | 2018-05-17 | Equivalent to Python 3.7.0rc1       |

+---------+------------+-------------------------------------+

| 0.5     | 2018-03-28 | Equivalent to Python 3.7.0b3        |

+---------+------------+-------------------------------------+