Question

Is it possible to write a decorator that creates many properties at once?

Like instead of writing

class Test:
    @property
    def a(self):
        return self.ref.a
    @property
    def b(self):
        return self.ref.b

I’d like to write

class Test:
    @properties("a", "b")
    def prop(self, name):
        return getattr(self.ref, name)

Is it possible? Do you recommend it?

Answer 1

Recall that a decorator

@decorator(dec_args)
def foo(args):
    pass

is just syntactic sugar for writing

def foo(args):
    pass
foo = decorator(dec_args)(foo)

So it is not possible for a method decorator to result in more than one method (or property, etc.) to be added to a class.

An alternative might be a class decorator that injects the properties:

def multi_property(prop, *names):
    def inner(cls):
        for name in names:
            setattr(cls, name, property(lambda self, name=name: prop(self, name)))
    return inner

@multi_property(prop, 'a', 'b')
class Test:
    pass

However it’d usually be clearer to have each property present within the body of the class:

a = forward_property('ref', 'a')
b = forward_property('ref', 'b')

where forward_property returns a property object as appropriate implementing the descriptor protocol. This is friendlier to documentation and other static analysis tools, as well as (usually) the reader.