PostgreSQL psycopg2 driver  accepts two syntaxes

        Plus a string for .pgpass file

def _postgresql(self, dbhost, dbport, dbname, dbuser, dbpass, dsn_style=None):  # noqa
        """PostgreSQL psycopg2 driver  accepts two syntaxes

        Plus a string for .pgpass file
        """
        dsn = []

        if dsn_style is None or dsn_style == 'all' or dsn_style == 'keyvalue':
            dsnstr = "host='{0}' dbname='{2}' user='{3}' password='{4}'"

            if dbport is not None:
                dsnstr += " port='{1}'"

            dsn.append(dsnstr.format(dbhost,
                                     dbport,
                                     dbname,
                                     dbuser,
                                     dbpass,))

        if dsn_style == 'all' or dsn_style == 'kwargs':
            dsnstr = "host='{0}', database='{2}', user='{3}', password='{4}'"
            if dbport is not None:
                dsnstr += ", port='{1}'"

            dsn.append(dsnstr.format(dbhost,
                                     dbport,
                                     dbname,
                                     dbuser,
                                     dbpass))

        if dsn_style == 'all' or dsn_style == 'uri':
            dsnstr = "postgresql://{user}:{password}@{host}/{name}"

            dsn.append(dsnstr.format(
                host="{host}:{port}".format(host=dbhost, port=dbport) if dbport else dbhost,  # noqa
                name=dbname, user=dbuser, password=dbpass))

        if dsn_style == 'all' or dsn_style == 'pgpass':
            dsn.append(':'.join(map(str, filter(
                None, [dbhost, dbport, dbname, dbuser, dbpass]))))

        return dsn