kedro.io.PickleLocalDataSet¶
-
class
kedro.io.
PickleLocalDataSet
(filepath, backend='pickle', load_args=None, save_args=None, version=None)[source]¶ Bases:
kedro.io.core.AbstractDataSet
,kedro.io.core.FilepathVersionMixIn
PickleLocalDataSet
loads and saves a Python object to a local pickle file. The underlying functionality is supported by the pickle and joblib libraries, so it supports all allowed options for loading and saving pickle files.Example:
from kedro.io import PickleLocalDataSet import pandas as pd dummy_data = pd.DataFrame({'col1': [1, 2], 'col2': [4, 5], 'col3': [5, 6]}) data_set = PickleLocalDataSet(filepath="data.pkl", backend='pickle', load_args=None, save_args=None) data_set.save(dummy_data) reloaded = data_set.load()
Attributes
PickleLocalDataSet.BACKENDS
Methods
PickleLocalDataSet.__init__
(filepath[, …])Creates a new instance of PickleLocalDataSet
pointing to a concrete filepath.PickleLocalDataSet.exists
()Checks whether a data set’s output already exists by calling the provided _exists() method. PickleLocalDataSet.from_config
(name, config)Create a data set instance using the configuration provided. PickleLocalDataSet.load
()Loads data by delegation to the provided load method. PickleLocalDataSet.release
()Release any cached data. PickleLocalDataSet.save
(data)Saves data by delegation to the provided save method. -
BACKENDS
= {'joblib': <module 'joblib' from '/home/circleci/.conda/envs/kedro_builder/lib/python3.6/site-packages/joblib/__init__.py'>, 'pickle': <module 'pickle' from '/home/circleci/.conda/envs/kedro_builder/lib/python3.6/pickle.py'>}¶
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__init__
(filepath, backend='pickle', load_args=None, save_args=None, version=None)[source]¶ Creates a new instance of
PickleLocalDataSet
pointing to a concrete filepath.PickleLocalDataSet
can use two backends to serialise objects to disk:pickle.dump: https://docs.python.org/3/library/pickle.html#pickle.dump
joblib.dump: https://pythonhosted.org/joblib/generated/joblib.dump.html
and it can use two backends to load serialised objects into memory:
pickle.load: https://docs.python.org/3/library/pickle.html#pickle.load
joblib.load: https://pythonhosted.org/joblib/generated/joblib.load.html
Joblib tends to exhibit better performance in case objects store NumPy arrays: http://gael-varoquaux.info/programming/new_low-overhead_persistence_in_joblib_for_big_data.html.
Parameters: - filepath (
str
) – path to a pkl file. - backend (
str
) – backend to use, must be one of [‘pickle’, ‘joblib’]. - load_args (
Optional
[Dict
[str
,Any
]]) – Options for loading pickle files. Refer to the help file ofpickle.load
orjoblib.load
for options. - save_args (
Optional
[Dict
[str
,Any
]]) – Options for saving pickle files. Refer to the help file ofpickle.dump
orjoblib.load
for options. - version (
Optional
[Version
]) – If specified, should be an instance ofkedro.io.core.Version
. If itsload
attribute is None, the latest version will be loaded. If itssave
attribute is None, save version will be autogenerated.
Raises: ValueError
– If ‘backend’ is not one of [‘pickle’, ‘joblib’].ImportError
– If ‘backend’ could not be imported.
Return type: None
- filepath (
-
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.
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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 forload
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 forsave
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.- name (
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load
()¶ Loads data by delegation to the provided load method.
Return type: Any
Returns: Data returned by the provided load method. Raises: DataSetError
– When underlying load method raises error.
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release
()¶ Release any cached data.
Raises: DataSetError
– when underlying exists method raises error.Return type: bool
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save
(data)¶ Saves data by delegation to the provided save method.
Parameters: data ( Any
) – the value to be saved by provided save method.Raises: DataSetError
– when underlying save method raises error.Return type: None
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