kedro.io.AbstractVersionedDataset

class kedro.io.AbstractVersionedDataset(filepath, version, exists_function=None, glob_function=None)

AbstractVersionedDataset is the base class for all versioned dataset implementations.

All datasets that implement versioning should extend this abstract class and implement the methods marked as abstract.

Example:

from pathlib import Path, PurePosixPath
import pandas as pd
from kedro.io import AbstractVersionedDataset


class MyOwnDataset(AbstractVersionedDataset):
    def __init__(self, filepath, version, param1, param2=True):
        super().__init__(PurePosixPath(filepath), version)
        self._param1 = param1
        self._param2 = param2

    def load(self) -> pd.DataFrame:
        load_path = self._get_load_path()
        return pd.read_csv(load_path)

    def save(self, df: pd.DataFrame) -> None:
        save_path = self._get_save_path()
        df.to_csv(str(save_path))

    def _exists(self) -> bool:
        path = self._get_load_path()
        return Path(path.as_posix()).exists()

    def _describe(self):
        return dict(version=self._version, param1=self._param1, param2=self._param2)

Example catalog.yml specification:

my_dataset:
    type: <path-to-my-own-dataset>.MyOwnDataset
    filepath: data/01_raw/my_data.csv
    versioned: true
    param1: <param1-value> # param1 is a required argument
    # param2 will be True by default

Methods

exists()	Checks whether a dataset's output already exists by calling the provided _exists() method.
from_config(name, config[, load_version, ...])	Create a dataset 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.
to_config()	Converts the dataset instance into a dictionary-based configuration for serialization.

__init__(filepath, version, exists_function=None, glob_function=None)

Creates a new instance of AbstractVersionedDataset.

Parameters:

• filepath (PurePosixPath) – Filepath in POSIX format to a file.

• version (Version | None) – 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.

• exists_function (Callable[[str], bool] | None) – Function that is used for determining whether a path exists in a filesystem.

• glob_function (Callable[[str], list[str]] | None) – Function that is used for finding all paths in a filesystem, which match a given pattern.

exists()

Checks whether a dataset’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 dataset 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 dataset is versioned. Has no effect on the dataset if versioning was not enabled.

• save_version (str | None) – Version string to be used for save operation if the dataset is versioned. Has no effect on the dataset if versioning was not enabled.

Return type:

AbstractDataset

Returns:

An instance of an AbstractDataset subclass.

Raises:

DatasetError – When the function fails to create the dataset from its config.

abstract 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.

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

abstract 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

to_config()

Converts the dataset instance into a dictionary-based configuration for serialization. Ensures that any subclass-specific details are handled, with additional logic for versioning and caching implemented for CachedDataset.

Adds a key for the dataset’s type using its module and class name and includes the initialization arguments.

For CachedDataset it extracts the underlying dataset’s configuration, handles the versioned flag and removes unnecessary metadata. It also ensures the embedded dataset’s configuration is appropriately flattened or transformed.

If the dataset has a version key, it sets the versioned flag in the configuration.

Removes the metadata key from the configuration if present.

Return type:

dict[str, Any]

Returns:

A dictionary containing the dataset’s type and initialization arguments.