def concat_key_values(dicts, keys, new_key, join_string):
    """
    Concatenate multiple dict fields into a new field
    """
    print("concat keys {}".format(keys))
    for d in dicts:
        concat = []

        for key in keys:
            if not key in d:
                continue
            concat.append(str(d[key]))

        d[new_key] = join_string.join(concat)

    return dicts