[Python-Dev] reducing self.x=x; self.y=y; self.z=z boilerplate code

Sat Jul 2 02:50:22 CEST 2005

Jp Calderone wrote:
> If you use vars(self).update(locals()), it even looks halfway
> pleasant ;) I'm not sure what python-dev's current opinion of
> vars(obj) is though (I'm hoping someone'll tell me).

http://docs.python.org/lib/built-in-funcs.html#l2h-76 is pretty clear:
 vars([object])
 Without arguments, return a dictionary corresponding to the current
 local symbol table. With a module, class or class instance object
 as argument (or anything else that has a __dict__ attribute),
 returns a dictionary corresponding to the object's symbol table.
 The returned dictionary should not be modified: the effects on the
 corresponding symbol table are undefined.
> Of course, both of these fall over for __slots__'ful classes. It'd be
> nice if there were a general way to deal with attributes of an
> instance, regardless of the implementation details of its memory
> layout.

I agree. Ideally I'd like this
 class grouping:
 __slots__ = True
 def __init__(self, .x, .y, .z):
 pass
to be equivalent to:
 class grouping:
 __slots__ = ["x", "y", "z"]
 def __init__(self, x, y, z):
 self.x = x
 del x
 self.y = y
 del y
 self.z = z
 del z
Cheers,
 Ralf