Method write

pandas/io/parquet.py:298–349

(
        self,
        df: DataFrame,
        path,
        compression: Literal["snappy", "gzip", "brotli"] | None = "snappy",
        index=None,
        partition_cols=None,
        storage_options: StorageOptions | None = None,
        filesystem=None,
        **kwargs,
    )

        self.api = fastparquet

    def write(
        self,
        df: DataFrame,
        path,
        compression: Literal["snappy", "gzip", "brotli"] | None = "snappy",
        index=None,
        partition_cols=None,
        storage_options: StorageOptions | None = None,
        filesystem=None,
        **kwargs,
    ) -> None:
        self.validate_dataframe(df)

        if "partition_on" in kwargs and partition_cols is not None:
            raise ValueError(
                "Cannot use both partition_on and "
                "partition_cols. Use partition_cols for partitioning data"
            )
        if "partition_on" in kwargs:
            partition_cols = kwargs.pop("partition_on")

        if partition_cols is not None:
            kwargs["file_scheme"] = "hive"

        if filesystem is not None:
            raise NotImplementedError(
                "filesystem is not implemented for the fastparquet engine."
            )

        # cannot use get_handle as write() does not accept file buffers
        path = stringify_path(path)
        if is_fsspec_url(path):
            fsspec = import_optional_dependency("fsspec")

            # if filesystem is provided by fsspec, file must be opened in 'wb' mode.
            kwargs["open_with"] = lambda path, _: fsspec.open(
                path, "wb", **(storage_options or {})
            ).open()
        elif storage_options:
            raise ValueError(
                "storage_options passed with file object or non-fsspec file path"
            )

        with catch_warnings(record=True):
            self.api.write(
                path,
                df,
                compression=compression,
                write_index=index,
                partition_on=partition_cols,
                **kwargs,
            )

    def read(
        self,