If I make a subclass of a built-in class, like this:
class mylist(list):
def __init__(self):
list.__init__(self)
Then it is valid for me to do this:
>>> x=mylist()
>>> x.hello=3
>>>
But I can't do this:
>>> y=list()
>>> y.hello=3
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'list' object has no attribute 'hello'
>>>
What is it that is special about built-in classes that prevents you
from adding methods or, uh, whatever the generic term is for sub-
variables? Is there a way to make your own classes restricted like
that?
OK thanks!
--
-dave----------------------------------------------------------------
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