``Type-checking'' with dir()

[Asun Friere]

harry.pehkonen at hotpop.com (Harry Pehkonen) wrote in message news:<70df36e9.0308161136.3c414a80 at posting.google.com>...
> In order to leave my classes open to receiving objects that are
> string-like, list-like, dictionary-like, etc, and not necessarily
> _exactly_ the built-in string, list, dictionary, etc types, I have the
> desire to just check if the necessary methods exist. 


Why do you have this desire?  If your program is usually going to be
passed lists etc, isn't that a lot of expensive LBYL checking to have
to go through?  Is there some reason that simply handling the Type or
Attribute (or Whatever) errors won't suffice?