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?
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.