unsupported narwhals import

[mattijn]

What happened?

I currently get this error when trying to import altair:

ImportError: cannot import name 'is_into_dataframe' from 'narwhals.dependencies' 

This part is not safe at the moment:

altair/altair/utils/_vegafusion_data.py

Line 8 in a0c091e

from narwhals.dependencies import is_into_dataframe

The function is_into_dataframe is introduced in narwhals v1.13.1, but our demand is:

altair/pyproject.toml

Line 23 in a0c091e

"narwhals>=1.5.2"

Btw, should this not be referenced by making use of the stable v1 of narwhals?

import narwhals.stable.v1 as nw
...
return isinstance(data, DataFrameLike) or nw.dependencies.is_into_dataframe(data)

I notice elsewhere we mixed the stable.v1 with just-import-direct approach:

altair/altair/utils/core.py

Lines 18 to 20 in a0c091e

	import narwhals.stable.v1 as nw
	from narwhals.dependencies import get_polars, is_pandas_dataframe
	from narwhals.typing import IntoDataFrame

What would you like to happen instead?

Probably best is to update the pyproject.toml file.

Which version of Altair are you using?

main