How to subclass Python list without type problems?
Firstly, I recommend you follow Björn Pollex's advice (+1).
To get past this particular problem (type(l2 + l3) == CustomList), you need to implement a custom __add__():
def __add__(self, rhs): return CustomList(list.__add__(self, rhs))And for extended slicing:
def __getitem__(self, item): result = list.__getitem__(self, item) try: return CustomList(result) except TypeError: return resultI also recommend...
pydoc list...at your command prompt. You'll see which methods list exposes and this will give you a good indication as to which ones you need to override.
You should probably read these two sections from the documentation:
Edit: In order to handle extended slicing, you should make your __getitem__-method handle slice-objects (see here, a little further down).