Inheritance question

[Alex Martelli]

Yannick Turgeon <nobody at nowhere.com> wrote:

> class A:
>     _value
>     __init__(self, value):
>         self._value = value
>         if value > 10:
>             set myself as an instance of B1   # How can I do that?

self.__class__ = B1

Whether you WANT to do that is quite another issue: you most likely
don't, though you wrongly believe you do.  Use a factory-function
pattern if you want to generate different possible classes, don't use
black magic such as changing an instance's class on the fly unless there
are _really good_ reasons (an example of a really good reason, IMHO, is
given by a recipe in the Cookbook that presents a bounded-ring-buffer
class... its instances commute from NotFull to Full classes once and for
all when they switch from non-full to full, NOT at instance generation
time...).


Alex