def test_from_variables(self) -> None:
v_level1 = xr.Variable("x", [1, 2, 3],
attrs={"unit": "m"},
encoding={"dtype": np.int32})
v_level2 = xr.Variable("x", ["a", "b", "c"],
attrs={"unit": "m"},
encoding={"dtype": "U"})
index = PandasMultiIndex.from_variables({
"level1": v_level1,
"level2": v_level2
})
expected_idx = pd.MultiIndex.from_arrays(
[v_level1.data, v_level2.data])
assert index.dim == "x"
assert index.index.equals(expected_idx)
assert index.index.name == "x"
assert index.index.names == ["level1", "level2"]
var = xr.Variable(("x", "y"), [[1, 2, 3], [4, 5, 6]])
with pytest.raises(ValueError,
match=r".*only accepts 1-dimensional variables.*"):
PandasMultiIndex.from_variables({"var": var})
v_level3 = xr.Variable("y", [4, 5, 6])
with pytest.raises(
ValueError,
match=r"unmatched dimensions for multi-index variables.*"):
PandasMultiIndex.from_variables({
"level1": v_level1,
"level3": v_level3
})
def test_from_variables(self):
v_level1 = xr.Variable("x", [1, 2, 3],
attrs={"unit": "m"},
encoding={"dtype": np.int32})
v_level2 = xr.Variable("x", ["a", "b", "c"],
attrs={"unit": "m"},
encoding={"dtype": "U"})
index, index_vars = PandasMultiIndex.from_variables({
"level1": v_level1,
"level2": v_level2
})
expected_idx = pd.MultiIndex.from_arrays(
[v_level1.data, v_level2.data])
assert index.dim == "x"
assert index.index.equals(expected_idx)
assert list(index_vars) == ["x", "level1", "level2"]
xr.testing.assert_equal(xr.IndexVariable("x", expected_idx),
index_vars["x"])
xr.testing.assert_identical(v_level1.to_index_variable(),
index_vars["level1"])
xr.testing.assert_identical(v_level2.to_index_variable(),
index_vars["level2"])
var = xr.Variable(("x", "y"), [[1, 2, 3], [4, 5, 6]])
with pytest.raises(ValueError,
match=r".*only accepts 1-dimensional variables.*"):
PandasMultiIndex.from_variables({"var": var})
v_level3 = xr.Variable("y", [4, 5, 6])
with pytest.raises(ValueError,
match=r"unmatched dimensions for variables.*"):
PandasMultiIndex.from_variables({
"level1": v_level1,
"level3": v_level3
})