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 ? David _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
