sublcassing dict without losing functionality

[Mathias Waack]

Steven Bethard wrote:

> I'd like to subclass dict to disallow overwriting of keys,
> something like:

<snip>

> The problem is, dict doesn't appear to call __setitem__ in any of
> the __init__ forms, so none of the following raise errors as I'd
> like them to:

<snap>

> etc.  Is there a simple way to override this behavior in dict
> without
> having to rewrite __init__?  There are so many cases in
> dict.__init__ that I'm hesitant to try to reproduce them all...

How about starting with UserDict (source comes with your python
distribution) and modifying it for your needs?

Mathias