def countPxlsPerClass(data, label_col = "Label"):
    """
    Counts amount of pixels per class label

    Parameters
    ----------
    data: numpy.dataframe
        dataframe containing data
    label_col: str ( optional)
        name of label column

    Examples
    --------)
    >>> countPxlsPerClass(data, "Label_nr")

    Returns
    -------
    list
        list of absolute value counts per class
    """
    return data[label_col].value_counts()