Bruno Desthuilliers wrote:
> You've already got the technical answer. About a possible design
flaw,
> it would seem to me that restricting the join() operation on specific
> subclasses breaks the LSP. OTOH, Python being dynamically typed,
> inheritence is merely an implementation detail, so that m
andy2o a écrit :
Hi all,
Sorry if the post's title is confusing... I'll explain:
I have a class, called A say, and N>1 subclasses of A, called
A1, A2, A3, ..., AN say.
Instances of each subclass can sensibly be joined together with other
instances of the *same subclass*. The syntax of the join me
>Assuming that A is a new-style class then if they have to be
>exactly the same type compare the types
Ah-ha! I didn't know that.
>if the 'other' value can be a subclass of self:
>
> def join(self, other):
> if not isinstance(other, type(self)):
> raise whatever
Simple and neat!
andy2o wrote:
> But I want to raise an exception if my code finds:
>
> f = A1()
> g = A2()
> f.join(g) #should raise exception, as cannot join an
> #instance of A1 to an instance of A2.
>
> How can I verify in a method defined in class A that the subclasses I
> am joining are exactly
Hi all,
Sorry if the post's title is confusing... I'll explain:
I have a class, called A say, and N>1 subclasses of A, called
A1, A2, A3, ..., AN say.
Instances of each subclass can sensibly be joined together with other
instances of the *same subclass*. The syntax of the join method is
identic
