kedro.extras.datasets.dask.ParquetDataSet¶

class kedro.extras.datasets.dask.ParquetDataSet(filepath, load_args=None, save_args=None, credentials=None, fs_args=None)[source]¶

Bases: kedro.io.core.AbstractDataSet

ParquetDataSet loads and saves data to parquet file(s). It uses Dask remote data services to handle the corresponding load and save operations: https://docs.dask.org/en/latest/remote-data-services.html

Example (AWS S3):

from kedro.extras.datasets.dask import ParquetDataSet
import pandas as pd
import dask.dataframe as dd

data = pd.DataFrame({'col1': [1, 2], 'col2': [4, 5],
                     'col3': [5, 6]})
ddf = dd.from_pandas(data, npartitions=2)

data_set = ParquetDataSet(
    filepath="s3://bucket_name/path/to/folder",
    credentials={
        'client_kwargs':{
            'aws_access_key_id': 'YOUR_KEY',
            'aws_secret_access_key': 'YOUR SECRET',
        }
    },
    save_args={"compression": "GZIP"}
)
data_set.save(ddf)
reloaded = data_set.load()

assert ddf.compute().equals(reloaded.compute())

Attributes

`ParquetDataSet.DEFAULT_LOAD_ARGS`
`ParquetDataSet.DEFAULT_SAVE_ARGS`
`ParquetDataSet.fs_args`	Property of optional file system parameters.

Methods

`ParquetDataSet.__init__`(filepath[, …])	Creates a new instance of `ParquetDataSet` pointing to concrete parquet files.
`ParquetDataSet.exists`()	Checks whether a data set’s output already exists by calling the provided _exists() method.
`ParquetDataSet.from_config`(name, config[, …])	Create a data set instance using the configuration provided.
`ParquetDataSet.load`()	Loads data by delegation to the provided load method.
`ParquetDataSet.release`()	Release any cached data.
`ParquetDataSet.save`(data)	Saves data by delegation to the provided save method.

DEFAULT_LOAD_ARGS = {}¶

DEFAULT_SAVE_ARGS = {'write_index': False}¶

__init__(filepath, load_args=None, save_args=None, credentials=None, fs_args=None)[source]¶

Creates a new instance of ParquetDataSet pointing to concrete parquet files.

Parameters:

filepath (str) – Filepath in POSIX format to a parquet file parquet collection or the directory of a multipart parquet.
load_args (Optional[Dict[str, Any]]) – Additional loading options dask.dataframe.read_parquet: https://docs.dask.org/en/latest/dataframe-api.html#dask.dataframe.read_parquet
save_args (Optional[Dict[str, Any]]) – Additional saving options for dask.dataframe.to_parquet: https://docs.dask.org/en/latest/dataframe-api.html#dask.dataframe.to_parquet
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]]) – Optional parameters to the backend file system driver: https://docs.dask.org/en/latest/remote-data-services.html#optional-parameters

Return type:

None

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.

fs_args¶

Property of optional file system parameters.

Return type:	`Dict`[`str`, `Any`]
Returns:	A dictionary of backend file system parameters, including credentials.

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.

release()¶

Release any cached data.

Raises:	`DataSetError` – when underlying release method raises error.
Return type:	`None`

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`