def read_mappings_from_dict(index_mapping):
    """
    Read event_class and event_type mappings from a python dict.
    """
    evclass = [[], [], []]
    evtype = [[], [], []]
    for v in index_mapping['classes']:
        evclass[0].append(v[0])
        evclass[1].append(v[1])
        evclass[2].append(v[2])

    for v in index_mapping['types']:
        evtype[0].append(v[0])
        evtype[1].append(v[1])
        evtype[2].append(v[2])

    return evclass, evtype