On Sun, Dec 12, 2010 at 3:35 AM, ernest <nfdi...@gmail.com> wrote: > Hi, > > I'd like to have a reference to an instance attribute as > default argument in a method. It doesn't work because > "self" is not defined at the time the method signature is > evaluated. For example: > > class C(object): > def __init__(self): > self.foo = 5 > def m(self, val=self.foo): > return val > > Raises NameError because 'self' is not defined. > The obvious solution is put val=None in the signature > and set val to the appropriate value inside the method > (if val is None: ...), but I wonder if there's another way.
Nope, not really. There are some more complicated slight variations on the same theme (e.g. hoisting the idiom into a decorator), but they're of fairly dubious merit; just use the straightforward idiom you already outlined. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
