Level.isnull()

>>> df = pd.DataFrame(
...     columns=["Country", "City", "Price"],
...     data=[
...         ("France", "Paris", 200.0),
...         ("Germany", "Berlin", 120),
...     ],
... )
>>> table = session.read_pandas(df, table_name="Example")
>>> cube = session.create_cube(table)
>>> l, m = cube.levels, cube.measures
>>> condition = l["City"].isnull()
>>> condition
l['Example', 'City', 'City'].isnull()
>>> m["City.isnull"] = condition
>>> m["City.notnull"] = ~condition
>>> cube.query(
...     m["City.isnull"],
...     m["City.notnull"],
...     levels=[l["Country"], l["City"]],
...     include_totals=True,
... )
               City.isnull City.notnull
Country City
Total                 True        False
France                True        False
        Paris        False         True
Germany               True        False
        Berlin       False         True