[Python-Dev] Python's C interface for types

[Giovanni Bajo]

On 26/01/2007 17.03, Thomas Wouters wrote:

>     How critical is the 'numeric' property of the nb_hash function?  I
>     can certainly honour it, but is it worth it?
> 
> [...]
> There's no strict requirement that 
> equal objects must have equal hashes, 

Uh? I thought that was the *only* strict requirement of hash. In fact the docs 
agree:

====================================================
__hash__( self)

Called for the key object for dictionary operations, and by the built-in 
function hash(). Should return a 32-bit integer usable as a hash value for 
dictionary operations. The only required property is that objects which 
compare equal have the same hash value; [...]
====================================================

I personally consider *very* important that hash(5.0) == hash(5) (and that 5.0 
== 5, of course).
-- 
Giovanni Bajo