def update_line(self, section, old_line, new_line, once=False):
try:<EOL><INDENT>s = self._get_section(section, create=False)<EOL><DEDENT>except KeyError:<EOL><INDENT>return <NUM_LIT:0><EOL><DEDENT>return s.update(old_line, new_line, once=once)<EOL>
Replace all lines matching `old_line` with `new_line`.

        If ``once`` is set to True, remove only the first instance.

        Returns:
            int: the number of updates performed