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.ExistsMixin
,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.save
(data)Saves data by delegation to the provided save method. -
BACKENDS
= {'joblib': <module 'joblib' from '/usr/local/anaconda3/envs/testing_37/lib/python3.7/site-packages/joblib/__init__.py'>, 'pickle': <module 'pickle' from '/usr/local/anaconda3/envs/testing_37/lib/python3.7/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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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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