clearing subclassed lists/dicts

[g2 at iowegian.com]

Hi All,

I've gotten interested in subclassing lists and dictionaries, and that got me
wondering if there's an elegant way to clear the contents of the underlying
type.

I tried a couple of things that I didn't really expect to work:

   >>> class L(list):
   ...    def clear(self):
   ...       self = []
   ...
   >>> l = L()
   >>> type(l)
   <class '__main__.L'>
   >>> l.clear()
   >>> type(l)
   <class '__main__.L'>
   >>> l.append(1)
   >>> l
   [1]
   >>> l.clear()
   >>> l
   [1]

   >>> class L2(list):
   ...    def clear(self):
   ...       del(self)
   ...
   >>> l2 = L2()
   >>> l2.append(1)
   >>> l2.clear()
   >>> l2
   [1]

as well as one I was pretty sure would:

   >>> class L3(list):
   ...    def clear(self):
   ...       while self:
   ...          del(self[-1])
   ...
   >>> l3 = L3()
   >>> l3.append(1)
   >>> l3.clear()
   >>> l3
   []

And it did work, but it doesn't seem particularly elegant.  Is there a better
way?

a-masochist-in-search-of-a-head-slap-ly y'rs,

=g2