marksweissma

def unpack_dict(d, keys=None, passed=None, filterNone=True):
    """
    Unpack nested dictionary with _ separted keys
    
    :param dict d: nested dictionary to unpack
    :param list keys: sequence of access keys
    :param dict passed: dict to update with flattened keys
    :param bool filterNone: filter out keys where value is None
    :return: flattened dict
    :rtype: dict