from_columns

classmethod NestedDtype.from_columns(columns: Mapping[str, pa.DataType]) → Self

Make NestedDtype from a mapping of column names and list item types.

Parameters:

columns (Mapping[str, pa.DataType]) – A mapping of column names and their item types. Since all fields are lists, the item types are inner types of the lists, not the list types themselves.

Returns:

The constructed NestedDtype.

Return type:

NestedDtype

Examples

>>> dtype = NestedDtype.from_columns({"a": pa.float64(), "b": pa.int64()})
>>> dtype
nested<a: [double], b: [int64]>
>>> assert (
...     dtype.pyarrow_dtype
...     == pa.struct({"a": pa.large_list(pa.float64()), "b": pa.large_list(pa.int64())})
... )