kedro_datasets.pandas.ParquetDataset¶

class kedro_datasets.pandas.ParquetDataset(*, filepath, load_args=None, save_args=None, version=None, credentials=None, fs_args=None, metadata=None)[source]¶

ParquetDataset loads/saves data from/to a Parquet file using an underlying filesystem (e.g.: local, S3, GCS). It uses pandas to handle the Parquet file.

Example usage for the YAML API:

boats:
  type: pandas.ParquetDataset
  filepath: data/01_raw/boats.parquet
  load_args:
    engine: pyarrow
    use_nullable_dtypes: True
  save_args:
    file_scheme: hive
    has_nulls: False
    engine: pyarrow

trucks:
  type: pandas.ParquetDataset
  filepath: abfs://container/02_intermediate/trucks.parquet
  credentials: dev_abs
  load_args:
    columns: [name, gear, disp, wt]
    index: name
  save_args:
    compression: GZIP
    partition_on: [name]

Example usage for the Python API:

from kedro_datasets.pandas import ParquetDataset
import pandas as pd

data = pd.DataFrame({"col1": [1, 2], "col2": [4, 5], "col3": [5, 6]})

dataset = ParquetDataset(filepath=tmp_path / "test.parquet")
dataset.save(data)
reloaded = dataset.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.
`preview`([nrows])	Generate a preview of the dataset with a specified number of rows.
`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, load_args=None, save_args=None, version=None, credentials=None, fs_args=None, metadata=None)[source]¶

Creates a new instance of ParquetDataset pointing to a concrete Parquet file on a specific filesystem.

Parameters:

filepath (str) – Filepath in POSIX format to a Parquet 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. It can also be a path to a directory. If the directory is provided then it can be used for reading partitioned parquet files. Note: http(s) doesn’t support versioning.
load_args (Optional[dict[str, Any]]) – Additional options for loading Parquet file(s). Here you can find all available arguments when reading single file: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_parquet.html Here you can find all available arguments when reading partitioned datasets: https://arrow.apache.org/docs/python/generated/pyarrow.parquet.ParquetDataset.html#pyarrow.parquet.ParquetDataset.read All defaults are preserved.
save_args (Optional[dict[str, Any]]) – Additional saving options for saving Parquet file(s). Here you can find all available arguments: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_parquet.html All defaults are preserved. partition_cols is not supported.
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).
metadata (Optional[dict[str, Any]]) – Any arbitrary metadata. This is ignored by Kedro, but may be consumed by users or external plugins.

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 (str | None) – 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 (str | None) – 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:: TypeVar(_DO)
Returns:: Data returned by the provided load method.
Raises:: DatasetError – When underlying load method raises error.

preview(nrows=5)[source]¶

Generate a preview of the dataset with a specified number of rows.

Parameters:: nrows (int) – The number of rows to include in the preview. Defaults to 5.
Returns:: A dictionary containing the data in a split format.
Return type:: dict

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:: str | None

resolve_save_version()¶

Compute the version the dataset should be saved with.

Return type:: str | None

save(data)¶

Saves data by delegation to the provided save method.

Parameters:

data (TypeVar(_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