""" feather-format compat """ from __future__ import annotations from typing import ( TYPE_CHECKING, Any, ) from pandas._config import using_pyarrow_string_dtype from pandas._libs import lib from pandas.compat._optional import import_optional_dependency from pandas.util._decorators import doc from pandas.util._validators import check_dtype_backend import pandas as pd from pandas.core.api import DataFrame from pandas.core.shared_docs import _shared_docs from pandas.io._util import arrow_string_types_mapper from pandas.io.common import get_handle if TYPE_CHECKING: from collections.abc import ( Hashable, Sequence, ) from pandas._typing import ( DtypeBackend, FilePath, ReadBuffer, StorageOptions, WriteBuffer, ) @doc(storage_options=_shared_docs["storage_options"]) def to_feather( df: DataFrame, path: FilePath | WriteBuffer[bytes], storage_options: StorageOptions | None = None, **kwargs: Any, ) -> None: """ Write a DataFrame to the binary Feather format. Parameters ---------- df : DataFrame path : str, path object, or file-like object {storage_options} **kwargs : Additional keywords passed to `pyarrow.feather.write_feather`. """ import_optional_dependency("pyarrow") from pyarrow import feather if not isinstance(df, DataFrame): raise ValueError("feather only support IO with DataFrames") with get_handle( path, "wb", storage_options=storage_options, is_text=False ) as handles: feather.write_feather(df, handles.handle, **kwargs) @doc(storage_options=_shared_docs["storage_options"]) def read_feather( path: FilePath | ReadBuffer[bytes], columns: Sequence[Hashable] | None = None, use_threads: bool = True, storage_options: StorageOptions | None = None, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, ) -> DataFrame: """ Load a feather-format object from the file path. Parameters ---------- path : str, path object, or file-like object String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``read()`` function. The string could be a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.feather``. columns : sequence, default None If not provided, all columns are read. use_threads : bool, default True Whether to parallelize reading using multiple threads. {storage_options} dtype_backend : {{'numpy_nullable', 'pyarrow'}}, default 'numpy_nullable' Back-end data type applied to the resultant :class:`DataFrame` (still experimental). Behaviour is as follows: * ``"numpy_nullable"``: returns nullable-dtype-backed :class:`DataFrame` (default). * ``"pyarrow"``: returns pyarrow-backed nullable :class:`ArrowDtype` DataFrame. .. versionadded:: 2.0 Returns ------- type of object stored in file Examples -------- >>> df = pd.read_feather("path/to/file.feather") # doctest: +SKIP """ import_optional_dependency("pyarrow") from pyarrow import feather # import utils to register the pyarrow extension types import pandas.core.arrays.arrow.extension_types # pyright: ignore[reportUnusedImport] # noqa: F401 check_dtype_backend(dtype_backend) with get_handle( path, "rb", storage_options=storage_options, is_text=False ) as handles: if dtype_backend is lib.no_default and not using_pyarrow_string_dtype(): return feather.read_feather( handles.handle, columns=columns, use_threads=bool(use_threads) ) pa_table = feather.read_table( handles.handle, columns=columns, use_threads=bool(use_threads) ) if dtype_backend == "numpy_nullable": from pandas.io._util import _arrow_dtype_mapping return pa_table.to_pandas(types_mapper=_arrow_dtype_mapping().get) elif dtype_backend == "pyarrow": return pa_table.to_pandas(types_mapper=pd.ArrowDtype) elif using_pyarrow_string_dtype(): return pa_table.to_pandas(types_mapper=arrow_string_types_mapper()) else: raise NotImplementedError