def get_namespaces(client):
    """Get a list of namespaces defined on the server.

    :param client: Connected aerospike client.
    :type client: aerospike.Client
    :return: namespaces
    :rtype: list
    :Example:
    >>> get_namespaces(client)
    ['foo', 'bar', 'baz']
    """
    data = client.info("namespaces").values()[0][1]
    return data.rstrip().split(';')