def _split_data(data):
    """Split the keys of the data between 'properties' and 'data'

    data: list (or None)
        Result of a SQL query

    Returns
    -------
    dict
    """
    if data is None:
        return data
    data = data[0]
    properties = ["iris", "city", "citycode", "label"]
    result = {k: data.pop(k) for k in properties}
    result['data'] = data
    return result