kedro.io.AbstractDataset¶
- class kedro.io.AbstractDataset[source]¶
AbstractDataset
is the base class for all dataset implementations.All dataset implementations should extend this abstract class and implement the methods marked as abstract. If a specific dataset implementation cannot be used in conjunction with the
ParallelRunner
, such user-defined dataset should have the attribute _SINGLE_PROCESS = True. Example:from pathlib import Path, PurePosixPath import pandas as pd from kedro.io import AbstractDataset class MyOwnDataset(AbstractDataset[pd.DataFrame, pd.DataFrame]): def __init__(self, filepath, param1, param2=True): self._filepath = PurePosixPath(filepath) self._param1 = param1 self._param2 = param2 def load(self) -> pd.DataFrame: return pd.read_csv(self._filepath) def save(self, df: pd.DataFrame) -> None: df.to_csv(str(self._filepath)) def _exists(self) -> bool: return Path(self._filepath.as_posix()).exists() def _describe(self): return dict(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 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.
save
(data)Saves data by delegation to the provided save method.
- exists()[source]¶
Checks whether a dataset’s output already exists by calling the provided _exists() method.
- Return type:
- 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)[source]¶
Create a dataset instance using the configuration provided.
- Parameters:
name (str) – Data set name.
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:
- Returns:
An instance of an
AbstractDataset
subclass.- Raises:
DatasetError – When the function fails to create the dataset from its config.
- abstract load()[source]¶
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()[source]¶
Release any cached data.
- Raises:
DatasetError – when underlying release method raises error.
- Return type:
- abstract save(data)[source]¶
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: