src/transformers/pipelines/base.py/PipelineDataFormat/__init__
class PipelineDataFormat:    def __init__(
        self,
        output_path: Optional[str],
        input_path: Optional[str],
        column: Optional[str],
        overwrite: bool = False,
    ):
        self.output_path = output_path
        self.input_path = input_path
        self.column = column.split(",") if column is not None else [""]
        self.is_multi_columns = len(self.column) > 1

        if self.is_multi_columns:
            self.column = [tuple(c.split("=")) if "=" in c else (c, c) for c in self.column]

        if output_path is not None and not overwrite:
            if exists(abspath(self.output_path)):
                raise OSError(f"{self.output_path} already exists on disk")

        if input_path is not None:
            if not exists(abspath(self.input_path)):
                raise OSError(f"{self.input_path} doesnt exist on disk")