kedro.extras.datasets.pandas.AppendableExcelDataSet

class kedro.extras.datasets.pandas.AppendableExcelDataSet(filepath, load_args=None, save_args=None)

AppendableExcelDataSet loads/saves data from/to a local Excel file opened in append mode. It uses pandas to handle the Excel file.

Example:

from kedro.extras.datasets.pandas import AppendableExcelDataSet
from kedro.extras.datasets.pandas import ExcelDataSet
import pandas as pd

data_1 = pd.DataFrame({'col1': [1, 2], 'col2': [4, 5],
                     'col3': [5, 6]})

data_2 = pd.DataFrame({'col1': [7, 8], 'col2': [5, 7]})

regular_ds = ExcelDataSet(filepath="/tmp/test.xlsx")
appendable_ds = AppendableExcelDataSet(
    filepath="/tmp/test.xlsx",
    save_args={"sheet_name": "my_sheet"},
    load_args={"sheet_name": "my_sheet"}
)

regular_ds.save(data_1)
appendable_ds.save(data_2)
reloaded = appendable_ds.load()
assert data_2.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.
save(data)	Saves data by delegation to the provided save method.

DEFAULT_LOAD_ARGS = {'engine': 'openpyxl'}

DEFAULT_SAVE_ARGS = {'index': False}

__init__(filepath, load_args=None, save_args=None)

Creates a new instance of AppendableExcelDataSet pointing to an existing local Excel file to be opened in append mode.

Parameters

• filepath (str) – Filepath in POSIX format to an existing local Excel file.

• load_args (Optional[Dict[str, Any]]) – Pandas options for loading Excel files. Here you can find all available arguments: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_excel.html All defaults are preserved, but “engine”, which is set to “openpyxl”.

• save_args (Optional[Dict[str, Any]]) – Pandas options for saving Excel files. Here you can find all available arguments: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.to_excel.html All defaults are preserved, but “index”, which is set to False. If you would like to specify options for the ExcelWriter, you can include them under “writer” key. Here you can find all available arguments: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.ExcelWriter.html Note: mode option of ExcelWriter is set to a and it can not be overridden.

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

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