[SciPy-User] [SciPy-user] code structure advise for a model

[Christopher Barker]

On 2/3/11 8:42 PM, David wrote:
> As for how to use inheritance: inheritance is tricky. One rule which
> works almost all the time to decide where B should derive from A is
> whether an instance of B can be used whenever an instance of A needs to
> be used (this is called the Liskov substitution principle if you want to
> shine in discussions).

There is also the classic way of thinking about OO:

use inheritance for a "is a" relationship:

a cat "is a" mammal.

> In that aspect, from what information you gave us, I don't see why Model
> should inherit from Params.

let's see: A Model "is a" set of parameters -- nope!

Another common relationship is the "has a" relationship:

A Model "has a" set of parameters -- yup!

So that means that your model would have a Params instance as an attribute.

> def create_params(some_param=0.0):
>       data = {"some_param": some_param, "other_param": ...}
>       return data

yup -- a simple dict may be all you need.

-Chris

-- 
Christopher Barker, Ph.D.
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