On 22/08/06, Marcus Goldfish <[EMAIL PROTECTED]> wrote: > Second, I think I found a partial answer in the Feb 22, 2005 tutor thread > http://aspn.activestate.com/ASPN/Mail/Message/python-tutor/2502290. > To preserve type, I need to override some special functions. In the case > of slicing, I need to override with something like this: > > def __getslice__(self, i, j): > return MyFoo(list.__getslice__(self, i, j))
__getslice__ is apparantly deprecated these days; you should override __getitem__ instead. (see the links I posted in my last message) > This seems straightforward, but raises other questions: what other functions > should I override, e.g., __add__, __radd__? Is there a preferred pythonic > way to creating a custom list container? Hmm, if you were talking about dicts, I would have said "Use UserDict.DictMixin". But there doesn't seem to be a UserList.ListMixin. There's a community one here: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/440656 that might work for you, but I haven't used it myself. > Finally, should I slice-copy my input list, inlist, to prevent side effects, > or is this handled by list? Should be handled by the list. For instance if x is a list, then list(x) is a copy of x (y=list(x) is equivalent to y=x[:]). But you should be able to test this easily enough.. -- John. _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
