def __init__(self, dbname, user=None, pswd=None, host=None, port=None):
        """Initialize the connection information

        :param dbname: database name
        :param user: user name
        :param pswd: user password
        :param host: host name
        :param port: host port number
        """
        self.dbname = dbname
        self.user = '' if user is None else " user=%s" % user
        self.pswd = '' if pswd is None else pswd % " password=%s"
        self.host = '' if host is None else "host=%s " % host
        self.port = '' if port is None else "port=%d " % port
        self.conn = None
dataset/ETHPy150Open perseas/Pyrseas/pyrseas/lib/dbconn.py/DbConnection.__init__/swapped operands of `%`