langchain/document_loaders/dataframe.py/DataFrameLoader/load
class DataFrameLoader:    def load(self) -> List[Document]:
        """Load from the dataframe."""
        result = []
        # For very large dataframes, this needs to yield instead of building a list
        # but that would require chaging return type to a generator for BaseLoader
        # and all its subclasses, which is a bigger refactor. Marking as future TODO.
        # This change will allow us to extend this to Spark and Dask dataframes.
        for _, row in self.data_frame.iterrows():
            text = row[self.page_content_column]
            metadata = row.to_dict()
            metadata.pop(self.page_content_column)
            result.append(Document(page_content=text, metadata=metadata))
        return result