Simple Python classproperty decorator

This module provides a simple way for defining class properties.

Install

You can install this Python module via pip:

pip install simple-classproperty

Otherwise the module can be downloaded from PyPI: https://pypi.org/project/simple-classproperty/

Usage

1. Import the module:

   from simple_classproperty import ClasspropertyMeta, classproperty

2. Create a class with a class property:

   class NewClass(metaclass=ClasspropertyMeta):
       _attr = "val"
   
       @classproperty
       def attr(cls):
           return cls._attr

   Don't forget to set the metaclass!
3. (Optional) Define also a setter and deleter for the newly created class property (this works like the standard python property):

   @attr.setter
   def attr(cls, value):
       cls._attr = value
   
   @attr.deleter
   def attr(cls):
       del cls._attr

Tips

The classproperty is also accessible from an instance:

instance = NewClass()
print(instance.attr)  # "val"

When the value of the property is changed from an instance object, the class property will be changed. All other instances will have this new value:

instance1 = NewClass()
instance2 = NewClass()

instance1.attr = "new"

print(instance1.attr)  # "new"
print(instance2.attr)  # "new"
print(NewClass.attr)   # "new"

This behavior is the same when a property gets deleted from an instance.