hashability

[Asun Friere]

On Aug 12, 12:15 pm, James Stroud <jstr... at mbi.ucla.edu> wrote:

> I realize I left out my use. The intent of the function is to flag
> objects that will make useful keys for a persistent dictionary. The
> {C():4}[C()] example demonstrates why I want to avoid certain types of
> keys--I don't want users to do things like {C():4, C():4}, which python
> happily allows but falls apart at the level of persistence.

What am I missing here?  How, in terms of persistence, is {C():4, C():
4} conceptually different from {'spam':4, 'ham':4}?