Question

Constructors in Python often look like this:

class SomeClass:
    def __init__(self, a, b = None, c = defC):
        self.a = a
        self.b = b or []
        self.c = c

Is there a shortcut for this, e.g. to simply define __init__(self,**kwargs) and use the keys as properties of self?

Answer 1

One problem with

self.__dict__.update(locals())

is that it includes self, so you get self.self. It would be better to filter self out of locals()

eg.

vars(self).update((k,v) for k,v in vars().items() if k != 'self')

You can defend against accidentally overwriting methods with this variation

vars(self).update((k,v) for k,v in vars().items()
                   if k != 'self' and k not in vars(self))

If you don’t want it to fail silently, you could also check beforehand like this

if any(k in vars(self) for k in vars()):
    raise blahblah
vars(self).update((k,v) for k,v in vars().items() if k != 'self')