On Fri, Jun 5, 2009 at 16:14, Michael McNeil Forbes <mfor...@physics.ubc.ca> wrote: > >>> np.array([0,1,2,3])[1:-1] > array([1, 2]) > > but > > >>> np.array([0,1,2,3])[np.s_[1:-1]] > array([1, 2, 3]) > >>> np.array([0,1,2,3])[np.index_exp[1:-1]] > array([1, 2, 3]) > > Possible fix: > class IndexExpression(object): > ... > def __len__(self): > return 0 > > (Presently this returns sys.maxint) > > Does this break anything (I can't find any coverage tests)? If not, I > will submit a ticket.
I think that getting rid of __getslice__ and __len__ should work better. I don't really understand what the logic was behind including them in the first place, though. I might be missing something. In [21]: %cpaste Pasting code; enter '--' alone on the line to stop. :class IndexExpression(object): : """ : A nicer way to build up index tuples for arrays. : : For any index combination, including slicing and axis insertion, : 'a[indices]' is the same as 'a[index_exp[indices]]' for any : array 'a'. However, 'index_exp[indices]' can be used anywhere : in Python code and returns a tuple of slice objects that can be : used in the construction of complex index expressions. : """ : : def __init__(self, maketuple): : self.maketuple = maketuple : : def __getitem__(self, item): : if self.maketuple and type(item) is not tuple: : return (item,) : else: : return item :-- In [22]: s2 = IndexExpression(False) In [23]: s2[1:-1] Out[23]: slice(1, -1, None) -- 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
