"Peter Maas" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED]
> This strikes me because if one can do this with instances of user > defined classes why not with lists? Trying to use lists as dict > keys yields "TypeError: list objects are unhashable". So why are > list objects unhashable and user defined objects hashable? For > user defined objects hash(x1) = id(x1), why not do the same > with lists? If d is a dict and t1 and t2 are tuples, and t1 == t2, then d[t1] and d[t2] are the same element. If lists used the id as the hash, this property would not hold for lists. Can you give me an example of a program for which you consider such behavior to be useful? -- http://mail.python.org/mailman/listinfo/python-list
