Return a CSV string representation of input data of type SupportsGeoInterface

[mattijn]

What is your suggestion?

The _data_to_csv_string function returns a NotImplementedError for objects that adhere to the type SupportsGeoInterface:

altair/altair/utils/data.py

Lines 284 to 291 in 596b282

	def _data_to_csv_string(data: Union[dict, pd.DataFrame, DataFrameLike]) -> str:
	"""return a CSV string representation of the input data"""
	check_data_type(data)
	if hasattr(data, "__geo_interface__"):
	raise NotImplementedError(
	"to_csv does not work with data that "
	"contains the __geo_interface__ attribute"
	)

The current error states:

to_csv does not work with data that contains the __geo_interface__ attribute.

This is too strong as it is in fact:

to_csv does not yet work with data that is of type SupportsGeoInterface.

Serialization to csv is just not done yet.

Have you considered any alternative solutions?