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https://github.com/yoelcortes/free_properties
Manage properties outside a class.
https://github.com/yoelcortes/free_properties
Last synced: about 2 months ago
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Manage properties outside a class.
- Host: GitHub
- URL: https://github.com/yoelcortes/free_properties
- Owner: yoelcortes
- License: mit
- Created: 2019-01-19T23:49:52.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2022-09-25T20:43:51.000Z (over 2 years ago)
- Last Synced: 2024-06-11T17:42:40.431Z (7 months ago)
- Language: Python
- Size: 1.28 MB
- Stars: 7
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.rst
- License: LICENSE.txt
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README
===============
free_properties
===============
.. image:: http://img.shields.io/pypi/v/free_properties.svg?style=flat
:target: https://pypi.python.org/pypi/free_properties
:alt: Version_status
.. image:: http://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat
:target: https://free_properties.readthedocs.io/en/latest/
:alt: Documentation
.. image:: http://img.shields.io/badge/license-MIT-blue.svg?style=flat
:target: https://github.com/yoelcortes/free_properties/blob/master/LICENSE.txt
:alt: license
.. contents::
What is free_properties?
------------------------
free_properties is a python package that features the FreeProperty class. A FreePropety object behaves just like its value property, allowing it to be used as a proxy for get, and set calculations like a python property.
Installation
------------
Get the latest version of free_properties from
https://pypi.python.org/pypi/free_properties/
If you have an installation of Python with pip, simple install it with:
$ pip install free_properties
To get the git version, run:
$ git clone git://github.com/yoelcortes/free_properties
Documentation
-------------
free_properties's documentation is available on the web:
http://free_properties.readthedocs.io/
Getting started
---------------
The PropertyFactory is a FreeProperty class creator that functions similar to Python 'property' objects. Use the PropertyFactory to create a Weight class which calculates weight based on density and volume:
.. code-block:: python
>>> from free_properties import PropertyFactory
>>> def getter(self):
... '''Weight (kg) based on volume (m^3).'''
... data = self.data
... rho = data['rho'] # Density (kg/m^3)
... vol = data['vol'] # Volume (m^3)
... return rho * vol
>>>
>>> def setter(self, weight):
... data = self.data
... rho = data['rho'] # Density (kg/m^3)
... data['vol'] = weight / rho
>>>
>>> # Initialize with a value getter, setter, and the class name.
>>> Weight = PropertyFactory(getter, setter, 'Weight', units='kg')
It is more convinient to use the PropertyFactory as a decorator:
.. code-block:: python
>>> @PropertyFactory(units='kg')
>>> def Weight(self):
... '''Weight (kg) based on volume (m^3).'''
... data = self.data
... rho = data['rho'] # Density (kg/m^3)
... vol = data['vol'] # Volume (m^3)
... return rho * vol
>>>
>>> @Weight.setter
>>> def Weight(self, weight):
... data = self.data
... rho = data['rho'] # Density (kg/m^3)
... data['vol'] = weight / rho
Create dictionaries of data and initialize new Weight objects:
.. code-block:: python
>>> water_data = {'rho': 1000, 'vol': 3}
>>> ethanol_data = {'rho': 789, 'vol': 3}
>>> weight_water = Weight('Water', water_data)
>>> weight_ethanol = Weight('Ethanol', ethanol_data)
>>> weight_water
>>> weight_ethanol
These properties behave just like their dynamic value:
.. code-block:: python
>>> weight_water + 30
3030
>>> weight_water + weight_ethanol
5367
Get and set the value through the 'value' attribute:
.. code-block:: python
>>> weight_water.value
3000
>>> weight_water.value = 4000
>>> weight_water.value
4000
>>> water_data # Note that the volume changed too
{'rho': 1000, 'vol': 4}
In place magic methods will also change the property value:
.. code-block:: python
>>> weight_water -= 1000
>>> weight_water
>>> water_data # The change also affects the original data
{'rho': 1000, 'vol': 3}
Use the property_array to manage free properties as an array:
.. code-block:: python
>>> from free_properties import property_array
>>> prop_arr = property_array([weight_water, weight_ethanol])
>>> prop_arr
property_array([3000.0, 2367.0], dtype=object)
>>> prop_arr.sum()
5367.0
Changing the values of a property_array changes the value of its properties:
.. code-block:: python
>>> # Addition in place
>>> prop_arr += 3000
>>> prop_arr
property_array([6000.0, 5367.0], dtype=object)
>>> # Note how the data also changes
>>> water_data
{'rho': 1000, 'vol': 6.0}
>>> ethanol_data
{'rho': 789, 'vol': 6.802281368821292}
>>> # Setting an item changes the property value
>>> prop_arr[1] = 2367
>>> ethanol_data
{'rho': 789, 'vol': 3}
New arrays have no connection to the property_array:
.. code-block:: python
>>> prop_arr - 1000 # Returns a new array
array([5000.0, 1367.0], dtype=object)
>>> water_data # Data remains unchanged
{'rho': 1000, 'vol': 6.0}
Latest source code
------------------
The latest development version of free_properties's sources can be obtained at:
https://github.com/yoelcortes/free_properties
Bug reports
-----------
To report bugs, please use the free_properties' Bug Tracker at:
https://github.com/yoelcortes/free_properties
License information
-------------------
See ``LICENSE.txt`` for information on the terms & conditions for usage
of this software, and a DISCLAIMER OF ALL WARRANTIES.
Although not required by the free_properties' license, if it is convenient for you,
please cite free_properties if used in your work. Please also consider contributing
any changes you make back, and benefit the community.
Citation
--------
To cite free_properties in publications use::
Yoel Cortes-Pena (2019). free_properties: Manage properties outside a class.
https://github.com/yoelcortes/free_properties