Source code for kedro.extras.datasets.pickle.pickle_dataset

"""``PickleDataSet`` loads/saves data from/to a Pickle file using an underlying
filesystem (e.g.: local, S3, GCS). The underlying functionality is supported by
the specified backend library passed in (defaults to the ``pickle`` library), so it
supports all allowed options for loading and saving pickle files.
import importlib
from copy import deepcopy
from pathlib import PurePosixPath
from typing import Any, Dict

import fsspec

from import (

# NOTE: kedro.extras.datasets will be removed in Kedro 0.19.0.
# Any contribution to datasets should be made in kedro-datasets
# in kedro-plugins (

[docs]class PickleDataSet(AbstractVersionedDataSet[Any, Any]): """``PickleDataSet`` loads/saves data from/to a Pickle file using an underlying filesystem (e.g.: local, S3, GCS). The underlying functionality is supported by the specified backend library passed in (defaults to the ``pickle`` library), so it supports all allowed options for loading and saving pickle files. Example usage for the `YAML API <\ data_catalog.html#use-the-data-catalog-with-the-yaml-api>`_: .. code-block:: yaml test_model: # simple example without compression type: pickle.PickleDataSet filepath: data/07_model_output/test_model.pkl backend: pickle final_model: # example with load and save args type: pickle.PickleDataSet filepath: s3://your_bucket/final_model.pkl.lz4 backend: joblib credentials: s3_credentials save_args: compress: lz4 Example usage for the `Python API <\ data_catalog.html#use-the-data-catalog-with-the-code-api>`_: :: >>> from kedro.extras.datasets.pickle import PickleDataSet >>> import pandas as pd >>> >>> data = pd.DataFrame({'col1': [1, 2], 'col2': [4, 5], >>> 'col3': [5, 6]}) >>> >>> data_set = PickleDataSet(filepath="test.pkl", backend="pickle") >>> >>> reloaded = data_set.load() >>> assert data.equals(reloaded) >>> >>> data_set = PickleDataSet(filepath="test.pickle.lz4", >>> backend="compress_pickle", >>> load_args={"compression":"lz4"}, >>> save_args={"compression":"lz4"}) >>> >>> reloaded = data_set.load() >>> assert data.equals(reloaded) """ DEFAULT_LOAD_ARGS = {} # type: Dict[str, Any] DEFAULT_SAVE_ARGS = {} # type: Dict[str, Any] # pylint: disable=too-many-arguments,too-many-locals
[docs] def __init__( self, filepath: str, backend: str = "pickle", load_args: Dict[str, Any] = None, save_args: Dict[str, Any] = None, version: Version = None, credentials: Dict[str, Any] = None, fs_args: Dict[str, Any] = None, ) -> None: """Creates a new instance of ``PickleDataSet`` pointing to a concrete Pickle file on a specific filesystem. ``PickleDataSet`` supports custom backends to serialise/deserialise objects. Example backends that are compatible (non-exhaustive): * `pickle` * `joblib` * `dill` * `compress_pickle` Example backends that are incompatible: * `torch` Args: filepath: Filepath in POSIX format to a Pickle file prefixed with a protocol like `s3://`. If prefix is not provided, `file` protocol (local filesystem) will be used. The prefix should be any protocol supported by ``fsspec``. Note: `http(s)` doesn't support versioning. backend: Backend to use, must be an import path to a module which satisfies the ``pickle`` interface. That is, contains a `load` and `dump` function. Defaults to 'pickle'. load_args: Pickle options for loading pickle files. You can pass in arguments that the backend load function specified accepts, e.g: pickle.load: joblib.load: dill.load: compress_pickle.load: All defaults are preserved. save_args: Pickle options for saving pickle files. You can pass in arguments that the backend dump function specified accepts, e.g: pickle.dump: joblib.dump: dill.dump: compress_pickle.dump: All defaults are preserved. version: If specified, should be an instance of ````. If its ``load`` attribute is None, the latest version will be loaded. If its ``save`` attribute is None, save version will be autogenerated. credentials: Credentials required to get access to the underlying filesystem. E.g. for ``GCSFileSystem`` it should look like `{"token": None}`. fs_args: Extra arguments to pass into underlying filesystem class constructor (e.g. `{"project": "my-project"}` for ``GCSFileSystem``), as well as to pass to the filesystem's `open` method through nested keys `open_args_load` and `open_args_save`. Here you can find all available arguments for `open`: All defaults are preserved, except `mode`, which is set to `wb` when saving. Raises: ValueError: If ``backend`` does not satisfy the `pickle` interface. ImportError: If the ``backend`` module could not be imported. """ # We do not store `imported_backend` as an attribute to be used in `load`/`save` # as this would mean the dataset cannot be deepcopied (module objects cannot be # pickled). The import here is purely to raise any errors as early as possible. # Repeated imports in the `load` and `save` methods should not be a significant # performance hit as Python caches imports. try: imported_backend = importlib.import_module(backend) except ImportError as exc: raise ImportError( f"Selected backend '{backend}' could not be imported. " "Make sure it is installed and importable." ) from exc if not ( hasattr(imported_backend, "load") and hasattr(imported_backend, "dump") ): raise ValueError( f"Selected backend '{backend}' should satisfy the pickle interface. " "Missing one of 'load' and 'dump' on the backend." ) _fs_args = deepcopy(fs_args) or {} _fs_open_args_load = _fs_args.pop("open_args_load", {}) _fs_open_args_save = _fs_args.pop("open_args_save", {}) _credentials = deepcopy(credentials) or {} protocol, path = get_protocol_and_path(filepath, version) if protocol == "file": _fs_args.setdefault("auto_mkdir", True) self._protocol = protocol self._fs = fsspec.filesystem(self._protocol, **_credentials, **_fs_args) super().__init__( filepath=PurePosixPath(path), version=version, exists_function=self._fs.exists, glob_function=self._fs.glob, ) self._backend = backend # Handle default load and save arguments self._load_args = deepcopy(self.DEFAULT_LOAD_ARGS) if load_args is not None: self._load_args.update(load_args) self._save_args = deepcopy(self.DEFAULT_SAVE_ARGS) if save_args is not None: self._save_args.update(save_args) _fs_open_args_save.setdefault("mode", "wb") self._fs_open_args_load = _fs_open_args_load self._fs_open_args_save = _fs_open_args_save
def _describe(self) -> Dict[str, Any]: return dict( filepath=self._filepath, backend=self._backend, protocol=self._protocol, load_args=self._load_args, save_args=self._save_args, version=self._version, ) def _load(self) -> Any: load_path = get_filepath_str(self._get_load_path(), self._protocol) with, **self._fs_open_args_load) as fs_file: imported_backend = importlib.import_module(self._backend) return imported_backend.load(fs_file, **self._load_args) # type: ignore def _save(self, data: Any) -> None: save_path = get_filepath_str(self._get_save_path(), self._protocol) with, **self._fs_open_args_save) as fs_file: try: imported_backend = importlib.import_module(self._backend) imported_backend.dump(data, fs_file, **self._save_args) # type: ignore except Exception as exc: raise DataSetError( f"{data.__class__} was not serialised due to: {exc}" ) from exc self._invalidate_cache() def _exists(self) -> bool: try: load_path = get_filepath_str(self._get_load_path(), self._protocol) except DataSetError: return False return self._fs.exists(load_path) def _release(self) -> None: super()._release() self._invalidate_cache() def _invalidate_cache(self) -> None: """Invalidate underlying filesystem caches.""" filepath = get_filepath_str(self._filepath, self._protocol) self._fs.invalidate_cache(filepath)