Method test_unique_1d

numpy/lib/tests/test_arraysetops.py:700–820

(self)

    @pytest.mark.filterwarnings(r"ignore:\w+ chararray \w+:DeprecationWarning")
    def test_unique_1d(self):

        a = [5, 7, 1, 2, 1, 5, 7] * 10
        b = [1, 2, 5, 7]
        i1 = [2, 3, 0, 1]
        i2 = [2, 3, 0, 1, 0, 2, 3] * 10
        c = np.multiply([2, 1, 2, 2], 10)

        # test for numeric arrays
        types = self.get_types()
        for dt in types:
            aa = np.array(a, dt)
            bb = np.array(b, dt)
            self.check_all(aa, bb, i1, i2, c, dt)

        # test for object arrays
        dt = 'O'
        aa = np.empty(len(a), dt)
        aa[:] = a
        bb = np.empty(len(b), dt)
        bb[:] = b
        self.check_all(aa, bb, i1, i2, c, dt)

        # test for structured arrays
        dt = [('', 'i'), ('', 'i')]
        aa = np.array(list(zip(a, a)), dt)
        bb = np.array(list(zip(b, b)), dt)
        self.check_all(aa, bb, i1, i2, c, dt)

        # test for ticket #2799
        aa = [1. + 0.j, 1 - 1.j, 1]
        assert_array_equal(
            np.sort(np.unique(aa)),
            [1. - 1.j, 1.],
        )

        # test for ticket #4785
        a = [(1, 2), (1, 2), (2, 3)]
        unq = [1, 2, 3]
        inv = [[0, 1], [0, 1], [1, 2]]
        a1 = unique(a)
        assert_array_equal(a1, unq)
        a2, a2_inv = unique(a, return_inverse=True)
        assert_array_equal(a2, unq)
        assert_array_equal(a2_inv, inv)

        # test for chararrays with return_inverse (gh-5099)
        a = np.char.chararray(5)
        a[...] = ''
        a2, a2_inv = np.unique(a, return_inverse=True)
        assert_array_equal(a2_inv, np.zeros(5))

        # test for ticket #9137
        a = []
        a1_idx = np.unique(a, return_index=True)[1]
        a2_inv = np.unique(a, return_inverse=True)[1]
        a3_idx, a3_inv = np.unique(a, return_index=True,
                                   return_inverse=True)[1:]