# -*-coding: utf8-*-
# utils/mixedmethod.py
"""This module implements a mixedmethod() decorator for class definitions.
Basic idea found here:
http://www.daniweb.com/software-development/python/code/406393/mixedmethod-mixes-class-and-instance-method-into-one
Usually, a class method works for an instance only.
If decorated with @classmethod it works for the class/type and for the
instance but ignores all instance data and works with the class data only.
Methods in a class decorated with @mixedmethod work with class/type and
instances in the same way BUT if the underlying object is a class/type
it works on the class/type data. If the underlying object is an instance
it works on the instance data. Thus, for instances modifications apply
to that individual instance only. For classes modifications apply on the
class level which applies changes to all instances created from that.
"""
from __future__ import print_function
from builtins import object
from functools import partial
[docs]class mixedmethod(object):
"""This decorator mutates a function defined in a class into a 'mixed'
class and instance method. Usage::
class Spam:
@mixedmethod
def egg(selforcls, *args, **kwargs):
# selforcls is the instance when called on an instance
# selforcls is the class when called on the class
pass
"""
def __init__(self, func):
self.func = func
def __get__(self, instance, cls):
if instance is None:
return partial(self.func, cls)
else:
return partial(self.func, instance)
if __name__ == '__main__':
class Spam(object):
bla = None
@mixedmethod
def ham(selforcls, val):
selforcls.bla = val
egg = Spam()
egg.ham(5)
Spam.ham(4)
print("Spam: ", Spam.bla, "egg:", egg.bla)
# vim: set ts=4 sts=4 sw=4 tw=0: