pandas (original) (raw)

Ok, the I now see where the reverse sorting happens in _codes_as_ordered (that was too much magic for my amateur numpy knowledge), but I still would vote for inlining this function.

There are also still two bugs, which didn't show up in the unittests :-( :

edit: The second (and third) is the problem with the "-1 to 0/len(levels)" conversation. Not sure why the first shows up, but I think because np.where(mask, n, n-codes-1) is only working in some specific cases, e.g. [0,1,2,3,4] becomes [5-0-1,5-1-1,...]=[4,3,2,1,0] but [0,1,1,2,3] becomes [3,2,2,1,0].

class TestCategorical(tm.TestCase):
    [....]
    def test_sort(self):

        [...]
        # reverse
        cat = Categorical(["a","c","c","b","d"], ordered=True)
        res = cat.order(ascending=False)
        exp_val = np.array(["d","c", "c", "b","a"],dtype=object)
        exp_levels = np.array(["a","b","c","d"],dtype=object)
        # FIXME: res.__array__() ends up as ['d' 'c' 'b' 'b' 'a']
        #self.assert_numpy_array_equal(res.__array__(), exp_val)
        self.assert_numpy_array_equal(res.levels, exp_levels)

        # some NaN positions
        cat = Categorical(["a","c","b","d", np.nan], ordered=True)
        res = cat.order(ascending=False, na_position='last')
        exp_val = np.array(["d","c","b","a", np.nan],dtype=object)
        exp_levels = np.array(["a","b","c","d"],dtype=object)
        # FIXME: IndexError: Out of bounds on buffer access (axis 0)
        #self.assert_numpy_array_equal(res.__array__(), exp_val)
        self.assert_numpy_array_equal(res.levels, exp_levels)

        cat = Categorical(["a","c","b","d", np.nan], ordered=True)
        res = cat.order(ascending=False, na_position='first')
        exp_val = np.array([np.nan, "d","c","b","a"],dtype=object)
        exp_levels = np.array(["a","b","c","d"],dtype=object)
        # FIXME: IndexError: Out of bounds on buffer access (axis 0)
        #self.assert_numpy_array_equal(res.__array__(), exp_val)
        self.assert_numpy_array_equal(res.levels, exp_levels)