kedro.extras.datasets.spark.SparkDataSet

class kedro.extras.datasets.spark.SparkDataSet(filepath, file_format='parquet', load_args=None, save_args=None, version=None, credentials=None)[source]

SparkDataSet loads and saves Spark dataframes. Example:

from pyspark.sql import SparkSession
from pyspark.sql.types import (StructField, StringType,
                               IntegerType, StructType)

from kedro.extras.datasets.spark import SparkDataSet

schema = StructType([StructField("name", StringType(), True),
                     StructField("age", IntegerType(), True)])

data = [('Alex', 31), ('Bob', 12), ('Clarke', 65), ('Dave', 29)]

spark_df = SparkSession.builder.getOrCreate()                                .createDataFrame(data, schema)

data_set = SparkDataSet(filepath="test_data")
data_set.save(spark_df)
reloaded = data_set.load()

reloaded.take(4)

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, file_format='parquet', load_args=None, save_args=None, version=None, credentials=None)[source]

Creates a new instance of SparkDataSet.

Parameters

  • filepath (str) – Filepath in POSIX format to a Spark dataframe. When using Databricks and working with data written to mount path points, specify filepath``s for (versioned) ``SparkDataSet``s starting with ``/dbfs/mnt.

  • file_format (str) – File format used during load and save operations. These are formats supported by the running SparkContext include parquet, csv. For a list of supported formats please refer to Apache Spark documentation at https://spark.apache.org/docs/latest/sql-programming-guide.html

  • load_args (Optional[Dict[str, Any]]) – Load args passed to Spark DataFrameReader load method. It is dependent on the selected file format. You can find a list of read options for each supported format in Spark DataFrame read documentation: https://spark.apache.org/docs/latest/api/python/reference/api/pyspark.sql.DataFrame.html

  • save_args (Optional[Dict[str, Any]]) – Save args passed to Spark DataFrame write options. Similar to load_args this is dependent on the selected file format. You can pass mode and partitionBy to specify your overwrite mode and partitioning respectively. You can find a list of options for each format in Spark DataFrame write documentation: https://spark.apache.org/docs/latest/api/python/reference/api/pyspark.sql.DataFrame.html

  • 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 to access the S3 bucket, such as key, secret, if filepath prefix is s3a:// or s3n://. Optional keyword arguments passed to hdfs.client.InsecureClient if filepath prefix is hdfs://. Ignored otherwise.

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

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

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 (Any) – 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