Antoon Pardon wrote: > It *is* a definition of an ordering. > > For something to be an ordering it has to be anti symmetric and transitive. > > The subset relationships on sets conform to these conditions so it is a > (partial) > ordering. Check your mathematic books, Why you would think this is abuse is > beyond me
Which is exactly why a < b on sets returns True xor False, but cmp(a,b) throws an exception. a <COMPARE> b is a local comparison, asking only for the relationship between two elements. In some bases, like the complex numbers, some comparisons are ill-defined.; in others, like sets, they're well-defined but don't give a total ordering. cmp(a,b) asks for their relative rankings in some total ordering. For a space that does not have a total ordering, cmp(a,b) is meaningless at best and dangerous at worst. It /should/ throw an exception when the results of cmp aren't well-defined, consistent, antisymmetric, and transitive. -- http://mail.python.org/mailman/listinfo/python-list
