kedro.extras.datasets.pickle.PickleDataSet

class kedro.extras.datasets.pickle.PickleDataSet(filepath, backend='pickle', load_args=None, save_args=None, version=None, credentials=None, fs_args=None)

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:

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:

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")
data_set.save(data)
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"})
data_set.save(data)
reloaded = data_set.load()
assert data.equals(reloaded)

Attributes

DEFAULT_LOAD_ARGS
DEFAULT_SAVE_ARGS

Methods

exists()	Checks whether a data set’s output already exists by calling the provided _exists() method.
from_config(name, config[, load_version, …])	Create a data set instance using the configuration provided.
load()	Loads data by delegation to the provided load method.
release()	Release any cached data.
resolve_load_version()	Compute the version the dataset should be loaded with.
resolve_save_version()	Compute the version the dataset should be saved with.
save(data)	Saves data by delegation to the provided save method.

DEFAULT_LOAD_ARGS: Dict[str, Any] = {}

DEFAULT_SAVE_ARGS: Dict[str, Any] = {}

__init__(filepath, backend='pickle', load_args=None, save_args=None, version=None, credentials=None, fs_args=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

Parameters

• filepath (str) – 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 (str) – 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 (Optional[Dict[str, Any]]) – Pickle options for loading pickle files. You can pass in arguments that the backend load function specified accepts, e.g: pickle.load: https://docs.python.org/3/library/pickle.html#pickle.load joblib.load: https://joblib.readthedocs.io/en/latest/generated/joblib.load.html dill.load: https://dill.readthedocs.io/en/latest/index.html#dill.load compress_pickle.load: https://lucianopaz.github.io/compress_pickle/html/api/compress_pickle.html#compress_pickle.compress_pickle.load All defaults are preserved.

• save_args (Optional[Dict[str, Any]]) – Pickle options for saving pickle files. You can pass in arguments that the backend dump function specified accepts, e.g: pickle.dump: https://docs.python.org/3/library/pickle.html#pickle.dump joblib.dump: https://joblib.readthedocs.io/en/latest/generated/joblib.dump.html dill.dump: https://dill.readthedocs.io/en/latest/index.html#dill.dump compress_pickle.dump: https://lucianopaz.github.io/compress_pickle/html/api/compress_pickle.html#compress_pickle.compress_pickle.dump All defaults are preserved.

• version (Optional[Version]) – If specified, should be an instance of kedro.io.core.Version. If its load attribute is None, the latest version will be loaded. If its save attribute is None, save version will be autogenerated.

• credentials (Optional[Dict[str, Any]]) – Credentials required to get access to the underlying filesystem. E.g. for GCSFileSystem it should look like {“token”: None}.

• fs_args (Optional[Dict[str, Any]]) – 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: https://filesystem-spec.readthedocs.io/en/latest/api.html#fsspec.spec.AbstractFileSystem.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.

exists()

Checks whether a data set’s output already exists by calling the provided _exists() method.

Return type

bool

Returns

Flag indicating whether the output already exists.

Raises

DataSetError – when underlying exists method raises error.

classmethod from_config(name, config, load_version=None, save_version=None)

Create a data set instance using the configuration provided.

Parameters

• name (str) – Data set name.

• config (Dict[str, Any]) – Data set config dictionary.

• load_version (Optional[str]) – Version string to be used for load operation if the data set is versioned. Has no effect on the data set if versioning was not enabled.

• save_version (Optional[str]) – Version string to be used for save operation if the data set is versioned. Has no effect on the data set if versioning was not enabled.

Return type

AbstractDataSet

Returns

An instance of an AbstractDataSet subclass.

Raises

DataSetError – When the function fails to create the data set from its config.

load()

Loads data by delegation to the provided load method.

Return type

~_DO

Returns

Data returned by the provided load method.

Raises

DataSetError – When underlying load method raises error.

release()

Release any cached data.

Raises

DataSetError – when underlying release method raises error.

Return type

None

resolve_load_version()

Compute the version the dataset should be loaded with.

Return type

Optional[str]

resolve_save_version()

Compute the version the dataset should be saved with.

Return type

Optional[str]

save(data)

Saves data by delegation to the provided save method.

Parameters

data (~_DI) – the value to be saved by provided save method.

Raises

• DataSetError – when underlying save method raises error.

• FileNotFoundError – when save method got file instead of dir, on Windows.

• NotADirectoryError – when save method got file instead of dir, on Unix.

Return type

None