There was some discussion on this recently. "==" actually has special fall-back code for strings, whereas "equal" is just a "raw" ufunc, and no ufunc's support strings.
http://www.mail-archive.com/numpy-discussion@scipy.org/msg21408.html Of course bool(NotImplemented) == True is sort of a separate issue that can be dealt with independently of whether ufuncs grow string support of not. Mike Pauli Virtanen wrote: > su, 2009-12-06 kello 23:01 -0800, Fernando Perez kirjoitti: > >> 2009/12/6 josef.pktd <josef.p...@gmail.com>: >> >>>>>> np.equal(np.arange(5),'a') >>>>>> >>> NotImplemented >>> >> Why is NotImplemented a *return* value? Normally NotImplementedError >> is a raised exception, but if it's not implemented, it shouldn't be >> returned as a value. >> > > Maybe it is so because some code paths are shared with the == operation? > > But in any case, NotImplemented should never be returned to the user -- > I believe it's only meant to be an internal value used in determining > the proper comparison operation between values. > > A bug ticket should be filed for this, I believe. > > -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
