MatplotlibDataset

MatplotlibDataset is used to load and save matplotlib figures.

kedro_datasets.matplotlib.MatplotlibDataset

MatplotlibDataset(
    *,
    filepath,
    fs_args=None,
    credentials=None,
    save_args=None,
    version=None,
    overwrite=False,
    metadata=None
)

Bases: AbstractVersionedDataset[Figure | list[Figure] | dict[str, Figure], NoReturn]

MatplotlibDataset saves one or more Matplotlib objects as image files to an underlying filesystem (e.g. local, S3, GCS).

Examples:

Using the YAML API:

output_plot:
  type: matplotlib.MatplotlibDataset
  filepath: data/08_reporting/output_plot.png
  save_args:
    format: png

Using the Python API:

>>> import matplotlib.pyplot as plt
>>> from kedro_datasets.matplotlib import MatplotlibDataset
>>>
>>> fig = plt.figure()
>>> plt.plot([1, 2, 3])
[<matplotlib.lines.Line2D object at 0x...>]
>>> plot_dataset = MatplotlibDataset(filepath=tmp_path / "data/08_reporting/output_plot.png")
>>> plt.close()
>>> plot_dataset.save(fig)

Saving a plot as a PDF file:

>>> import matplotlib.pyplot as plt
>>> from kedro_datasets.matplotlib import MatplotlibDataset
>>>
>>> fig = plt.figure()
>>> plt.plot([1, 2, 3])
[<matplotlib.lines.Line2D object at 0x...>]
>>> pdf_plot_dataset = MatplotlibDataset(
...     filepath=tmp_path / "data/08_reporting/output_plot.pdf", save_args={"format": "pdf"}
... )
>>> plt.close()
>>> pdf_plot_dataset.save(fig)

Saving multiple plots in a folder, using a dictionary:

>>> import matplotlib.pyplot as plt
>>> from kedro_datasets.matplotlib import MatplotlibDataset
>>>
>>> plots_dict = {}
>>> for colour in ["blue", "green", "red"]:
...     plots_dict[f"{colour}.png"] = plt.figure()
...     plt.plot([1, 2, 3], color=colour)
...
[<matplotlib.lines.Line2D object at 0x...>]
[<matplotlib.lines.Line2D object at 0x...>]
[<matplotlib.lines.Line2D object at 0x...>]
>>> plt.close("all")
>>> dict_plot_dataset = MatplotlibDataset(filepath=tmp_path / "data/08_reporting/plots")
>>> dict_plot_dataset.save(plots_dict)

Parameters:

• filepath (str) –

  Filepath in POSIX format to save Matplotlib objects to, 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.

• fs_args (dict[str, Any] | None, default: None ) –

  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 key 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 wb when saving.

• credentials (dict[str, Any] | None, default: None ) –

  Credentials required to get access to the underlying filesystem. E.g. for S3FileSystem it should look like: {'key': '<id>', 'secret': '<key>'}}

• save_args (dict[str, Any] | None, default: None ) –

  Save args passed to plt.savefig. See https://matplotlib.org/api/_as_gen/matplotlib.pyplot.savefig.html

• version (Version | None, default: 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.

• overwrite (bool, default: False ) –

  If True, any existing image files will be removed. Only relevant when saving multiple Matplotlib objects at once.

• metadata (dict[str, Any] | None, default: None ) –

  Any arbitrary Any arbitrary metadata. This is ignored by Kedro, but may be consumed by users or external plugins.

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def __init__(  # noqa: PLR0913
    self,
    *,
    filepath: str,
    fs_args: dict[str, Any] | None = None,
    credentials: dict[str, Any] | None = None,
    save_args: dict[str, Any] | None = None,
    version: Version | None = None,
    overwrite: bool = False,
    metadata: dict[str, Any] | None = None,
) -> None:
    """Creates a new instance of ``MatplotlibDataset``.

    Args:
        filepath: Filepath in POSIX format to save Matplotlib objects to, 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``.
        fs_args: 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 key `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 `wb` when saving.
        credentials: Credentials required to get access to the underlying filesystem.
            E.g. for ``S3FileSystem`` it should look like:
            `{'key': '<id>', 'secret': '<key>'}}`
        save_args: Save args passed to `plt.savefig`. See
            https://matplotlib.org/api/_as_gen/matplotlib.pyplot.savefig.html
        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.
        overwrite: If True, any existing image files will be removed.
            Only relevant when saving multiple Matplotlib objects at
            once.
        metadata: Any arbitrary Any arbitrary metadata.
            This is ignored by Kedro, but may be consumed by users or external plugins.
    """
    _credentials = deepcopy(credentials) or {}
    _fs_args = deepcopy(fs_args) or {}
    _fs_open_args_save = _fs_args.pop("open_args_save", {})
    _fs_open_args_save.setdefault("mode", "wb")

    protocol, path = get_protocol_and_path(filepath, version)
    if protocol == "file":
        _fs_args.setdefault("auto_mkdir", True)

    self._protocol = protocol
    self._fs = fsspec.filesystem(self._protocol, **_credentials, **_fs_args)

    self.metadata = metadata

    super().__init__(
        filepath=PurePosixPath(path),
        version=version,
        exists_function=self._fs.exists,
        glob_function=self._fs.glob,
    )

    self._fs_open_args_save = _fs_open_args_save

    # Handle default save arguments
    self._save_args = {**self.DEFAULT_SAVE_ARGS, **(save_args or {})}

    if overwrite and version is not None:
        warn(
            "Setting 'overwrite=True' is ineffective if versioning "
            "is enabled, since the versioned path must not already "
            "exist; overriding flag with 'overwrite=False' instead."
        )
        overwrite = False
    self._overwrite = overwrite

DEFAULT_SAVE_ARGS class-attribute instance-attribute

DEFAULT_SAVE_ARGS = {}

_fs instance-attribute

_fs = filesystem(_protocol, **_credentials, **_fs_args)

_fs_open_args_save instance-attribute

_fs_open_args_save = _fs_open_args_save

_overwrite instance-attribute

_overwrite = overwrite

_protocol instance-attribute

_protocol = protocol

_save_args instance-attribute

_save_args = {
    None: DEFAULT_SAVE_ARGS,
    None: save_args or {},
}

metadata instance-attribute

metadata = metadata

_describe

_describe()

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def _describe(self) -> dict[str, Any]:
    return {
        "filepath": self._filepath,
        "protocol": self._protocol,
        "save_args": self._save_args,
        "version": self._version,
    }

_exists

_exists()

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def _exists(self) -> bool:
    load_path = get_filepath_str(self._get_load_path(), self._protocol)
    return self._fs.exists(load_path)

_invalidate_cache

_invalidate_cache()

Invalidate underlying filesystem caches.

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def _invalidate_cache(self) -> None:
    """Invalidate underlying filesystem caches."""
    filepath = get_filepath_str(self._filepath, self._protocol)
    self._fs.invalidate_cache(filepath)

_release

_release()

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def _release(self) -> None:
    super()._release()
    self._invalidate_cache()

_save_to_fs

_save_to_fs(full_key_path, plot)

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def _save_to_fs(self, full_key_path: str, plot: Figure):
    bytes_buffer = io.BytesIO()
    plot.savefig(bytes_buffer, **self._save_args)

    with self._fs.open(full_key_path, **self._fs_open_args_save) as fs_file:
        fs_file.write(bytes_buffer.getvalue())

load

load()

Loading is not supported for MatplotlibDataset.

Raises:

• DatasetError –

  When called with any arguments.

Returns:

• NoReturn –

  Never returns as it always raises an exception.

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def load(self) -> NoReturn:
    """
    Loading is not supported for MatplotlibDataset.

    Raises:
        DatasetError: When called with any arguments.

    Returns:
        Never returns as it always raises an exception.
    """
    raise DatasetError(f"Loading not supported for '{self.__class__.__name__}'")

preview

preview()

Generates a preview of the matplotlib dataset as a base64 encoded image.

Returns:

• str –

  A base64 encoded string representing the matplotlib plot image.

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def preview(self) -> ImagePreview:
    """
    Generates a preview of the matplotlib dataset as a base64 encoded image.

    Returns:
        str: A base64 encoded string representing the matplotlib plot image.
    """
    load_path = get_filepath_str(self._get_load_path(), self._protocol)
    with self._fs.open(load_path, mode="rb") as img_file:
        base64_bytes = base64.b64encode(img_file.read())
    return ImagePreview(base64_bytes.decode("utf-8"))

save

save(data)

Source code in kedro_datasets/matplotlib/matplotlib_dataset.py

def save(self, data: Figure | (list[Figure] | dict[str, Figure])) -> None:
    save_path = self._get_save_path()

    if isinstance(data, list | dict) and self._overwrite and self._exists():
        self._fs.rm(get_filepath_str(save_path, self._protocol), recursive=True)

    if isinstance(data, list):
        for index, plot in enumerate(data):
            full_key_path = get_filepath_str(
                save_path / f"{index}.png", self._protocol
            )
            self._save_to_fs(full_key_path=full_key_path, plot=plot)
    elif isinstance(data, dict):
        for plot_name, plot in data.items():
            full_key_path = get_filepath_str(save_path / plot_name, self._protocol)
            self._save_to_fs(full_key_path=full_key_path, plot=plot)
    else:
        full_key_path = get_filepath_str(save_path, self._protocol)
        self._save_to_fs(full_key_path=full_key_path, plot=data)

    plt.close("all")

    self._invalidate_cache()