Method test_shift

xarray/tests/test_variable.py:1494–1527

(self, fill_value)

    @pytest.mark.parametrize("fill_value", [dtypes.NA, 2, 2.0])
    def test_shift(self, fill_value):
        v = Variable("x", [1, 2, 3, 4, 5])

        assert_identical(v, v.shift(x=0))
        assert v is not v.shift(x=0)

        expected = Variable("x", [np.nan, np.nan, 1, 2, 3])
        assert_identical(expected, v.shift(x=2))

        if fill_value == dtypes.NA:
            # if we supply the default, we expect the missing value for a
            # float array
            fill_value_exp = np.nan
        else:
            fill_value_exp = fill_value

        expected = Variable("x", [fill_value_exp, 1, 2, 3, 4])
        assert_identical(expected, v.shift(x=1, fill_value=fill_value))

        expected = Variable("x", [2, 3, 4, 5, fill_value_exp])
        assert_identical(expected, v.shift(x=-1, fill_value=fill_value))

        expected = Variable("x", [fill_value_exp] * 5)
        assert_identical(expected, v.shift(x=5, fill_value=fill_value))
        assert_identical(expected, v.shift(x=6, fill_value=fill_value))

        with pytest.raises(ValueError, match=r"dimension"):
            v.shift(z=0)

        v = Variable("x", [1, 2, 3, 4, 5], {"foo": "bar"})
        assert_identical(v, v.shift(x=0))

        expected = Variable("x", [fill_value_exp, 1, 2, 3, 4], {"foo": "bar"})
        assert_identical(expected, v.shift(x=1, fill_value=fill_value))

    def test_shift2d(self):
        v = Variable(("x", "y"), [[1, 2], [3, 4]])