def state_part_number(self, s):
        m = self._partExpr.match(s)
        if m is not None:
            self.parts = [1 - int(p) for p in m.groups()[0].split('.')]
            return m.end()
        else:
            self.parts = []
            return 0
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/mail/imap4.py/_FetchParser.state_part_number/swapped operands of `-`