Alan Isaac wrote:
> > At Friday 10/11/2006 14:11, Alan G Isaac wrote:
> > >class Params:
> > > def __init__(self,**kwargs):
> > > #set lots of default values
> > > ...
> > > #set the deviations from defaults
> > > self.__dict__.update(kwargs)
> > >
> > >Is this a reasonable approach overall?
> > >(Including the last line.)
>
>
> "Gabriel Genellina" wrote in message
> news:[EMAIL PROTECTED]
> > I'm not sure what you want to do exactly, but a class attribute acts
> > as a default instance attribute.
>
> Yes. I am sorry my question was not clearer.
> There are *many* parameters,
> and the list can change,
> so I want to avoid listing them all in the Param class's __init__ function,
> using the strategy above.
>
> Q1: Is this approach reasonable?
> (This is a newbie question about unforseen hazards.)
> Q2: Is it horrible design to isolate the parameters in a separate class?
> (Comment: currently several classes may rely on (parts of) the same
> parameter set.)
>
> Thanks,
> Alan Isaac
Hi,
I kind of had a similar problem when I was developing a 3d OO engine.
I had many
bigger things composed of lots of little things, and a lot of code was
spent
initializing the little things in constructors.
So I just passed a reference of the bigger thing to the little thing in
its constructor, thus saving a lot
of parameter passing and variable setup and copying. In the following
example, big is passed to
little's constructor, instead of all of big's variables.
ie.
class big:
def __init__(self):
self.v1 = ...
self.v2 = ...
self.objects = []
def assemble(self):
self.objects.append(little(self, 1))
self.objects.append(little(self,2))
class little:
def __init__(self, big, n):
self.big = big # Now little has access to v1, v2 by self.big.v1
etc
self.n = n # This makes it different
def a_function(self):
do_something(self.big.v1, self.big.v2)
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