kedro.extras.datasets.pandas.GenericDataSet¶

class kedro.extras.datasets.pandas.GenericDataSet(filepath, file_format, load_args=None, save_args=None, version=None, credentials=None, fs_args=None)[source]¶

pandas.GenericDataSet loads/saves data from/to a data file using an underlying filesystem (e.g.: local, S3, GCS). It uses pandas to dynamically select the appropriate type of read/write target on a best effort basis.

Example usage for the YAML API:

cars:
  type: pandas.GenericDataSet
  file_format: csv
  filepath: s3://data/01_raw/company/cars.csv
  load_args:
    sep: ","
    na_values: ["#NA", NA]
  save_args:
    index: False
    date_format: "%Y-%m-%d"

This second example is able to load a SAS7BDAT file via the pd.read_sas method. Trying to save this dataset will raise a DataSetError since pandas does not provide an equivalent pd.DataFrame.to_sas write method.

flights:
   type: pandas.GenericDataSet
   file_format: sas
   filepath: data/01_raw/airplanes.sas7bdat
   load_args:
      format: sas7bdat

Example usage for the Python API:

from kedro.extras.datasets.pandas import GenericDataSet
import pandas as pd

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

data_set = GenericDataSet(filepath="test.csv", file_format='csv')
data_set.save(data)
reloaded = data_set.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.
`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, load_args=None, save_args=None, version=None, credentials=None, fs_args=None)[source]¶

Creates a new instance of GenericDataSet pointing to a concrete data file on a specific filesystem. The appropriate pandas load/save methods are dynamically identified by string matching on a best effort basis.

Parameters

filepath (str) – Filepath in POSIX format to a 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. Key assumption: The first argument of either load/save method points to a filepath/buffer/io type location. There are some read/write targets such as ‘clipboard’ or ‘records’ that will fail since they do not take a filepath like argument.
file_format (str) – String which is used to match the appropriate load/save method on a best effort basis. For example if ‘csv’ is passed in the pandas.read_csv and pandas.DataFrame.to_csv will be identified. An error will be raised unless at least one matching read_{file_format} or to_{file_format} method is identified.
load_args (Optional[Dict[str, Any]]) – Pandas options for loading files. Here you can find all available arguments: https://pandas.pydata.org/pandas-docs/stable/reference/io.html All defaults are preserved.
save_args (Optional[Dict[str, Any]]) – Pandas options for saving files. Here you can find all available arguments: https://pandas.pydata.org/pandas-docs/stable/reference/io.html All defaults are preserved, but “index”, which is set to False.
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), as well as to pass to the filesystem’s open method through nested keys open_args_load and open_args_save. Here you can find all available arguments for open: https://filesystem-spec.readthedocs.io/en/latest/api.html#fsspec.spec.AbstractFileSystem.open All defaults are preserved, except mode, which is set to r when loading and to w when saving.

Raises

DataSetError – Will be raised if at least less than one appropriate read or write methods are identified.

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: ~_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: 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 (~_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