On Wed, Mar 11, 2009 at 22:49, David Cournapeau <courn...@gmail.com> wrote: > On Thu, Mar 12, 2009 at 5:36 AM, Robert Kern <robert.k...@gmail.com> wrote: >> On Wed, Mar 11, 2009 at 15:06, David Cournapeau <courn...@gmail.com> wrote: >>> Hi, >>> >>> I was looking at #936, to implement correctly the hashing protocol for >>> dtypes. Am I right to believe that tp_hash should recursively descend >>> fields for compound dtypes, and the hash value should depend on the >>> size/ndim/typenum/byteorder for each "atomic" dtype + fields name (and >>> titles) ? Contrary to comparison, we can't reuse the python C api, >>> since PyObject_Hash cannot be applied to the fields dict, right ? >> >> Usually, one constructs a hashable analogue; e.g. taking the .descr >> and converting all of the lists to tuples. Then use PyObject_Hash on >> that. > > Is the .descr of two dtypes guaranteed to be equal whenever the dtypes > are equal ? It is not obvious to me that PyArray_EquivTypes is > equivalent to comparing the descr ?
It was an example. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion