How to do Obj-C Categories in Python?

Question

Obj-C (which I have not used for a long time) has something called categories to extend classes. Declaring a category with new methods and compiling it into your program, all in

Answer 1

Python's setattr function makes this easy.

# categories.py

class category(object):
    def __init__(self, mainModule, override = True):
        self.mainModule = mainModule
        self.override = override

    def __call__(self, function):
        if self.override or function.__name__ not in dir(self.mainModule):
            setattr(self.mainModule, function.__name__, function)

 

# categories_test.py

import this
from categories import category

@category(this)
def all():
    print "all things are this"

this.all()
>>> all things are this