A simple decorator for write-only attributes

readme.md

It's the Python feature we've all been waiting for — write-only attributes. This simple decorator makes it so all your attributes are write-only:

@kablooey
class Foo:
    def __init__(self, x):
        self.x = x

Set these attributes to your heart's content:

foo = Foo(1)
foo.x = 2
foo.x = 3

Knowing that they are safely write-only — keeping them locked aray from prying eyes:

print(foo.x)

The above code would cause the following exception:

Traceback (most recent call last):
  File "...", line ..., in <module>
    print(foo.x)
          ^^^^^
  File "...", line ..., in __get__
    raise Exception("Bang!")
Exception: Bang!

kablooey.py

def kablooey(cls):
    instances = {}

    class Bang:
        def __init__(self, name):
            self.name = name

        def __get__(self, instance, owner):
            raise Exception("Bang!")

        def __set__(self, instance, value):
            instances[(id(instance), self.name)] = value

    og_setattr = cls.__setattr__

    def _setattr(instance, name, value):
        if not isinstance(cls.__dict__.get(name, None), Bang):
            type.__setattr__(cls, name, Bang(name))
        og_setattr(instance, name, value)

    cls.__setattr__ = _setattr
    return cls