Checks to see if a directory with the name of the specified dataset exists
    in the data home directory, found with ``get_data_home``.

    Parameters
    ----------
    dataset : str
        The name of the dataset; should either be a folder in data home or
        specified in the yellowbrick.datasets.DATASETS variable.

    data_home : str, optional
        The path on disk where data is stored. If not passed in, it is looked
        up from YELLOWBRICK_DATA or the default returned by ``get_data_home``.

    Returns
    -------
    exists : bool
        If a folder with the dataset name is in the data home directory.

def dataset_exists(dataset, data_home=None):
    """
    Checks to see if a directory with the name of the specified dataset exists
    in the data home directory, found with ``get_data_home``.

    Parameters
    ----------
    dataset : str
        The name of the dataset; should either be a folder in data home or
        specified in the yellowbrick.datasets.DATASETS variable.

    data_home : str, optional
        The path on disk where data is stored. If not passed in, it is looked
        up from YELLOWBRICK_DATA or the default returned by ``get_data_home``.

    Returns
    -------
    exists : bool
        If a folder with the dataset name is in the data home directory.
    """
    data_home = get_data_home(data_home)
    path = os.path.join(data_home, dataset)

    return os.path.exists(path) and os.path.isdir(path)