- Dataset.columns(fetch_if_missing: bool = True) Optional[List[str]] #
Returns the columns of this Dataset.
If this dataset consists of more than a read, or if the schema can’t be determined from the metadata provided by the datasource, or if
fetch_if_missing=True(the default), then this operation will trigger execution of the lazy transformations performed on this dataset.
Time complexity: O(1)
>>> import ray >>> # Create dataset from synthetic data. >>> ds = ray.data.range(1000) >>> ds.columns() ['id']
fetch_if_missing – If True, synchronously fetch the column names from the schema if it’s not known. If False, None is returned if the schema is not known. Default is True.
A list of the column names for this Dataset or None if schema is not known and