mailbox.py 文件源码

def _install_message(self, message):
        """Format a message and blindly write to self._file."""
        from_line = None
        if isinstance(message, str) and message.startswith('From '):
            newline = message.find('\n')
            if newline != -1:
                from_line = message[:newline]
                message = message[newline + 1:]
            else:
                from_line = message
                message = ''
        elif isinstance(message, _mboxMMDFMessage):
            from_line = 'From ' + message.get_from()
        elif isinstance(message, email.message.Message):
            from_line = message.get_unixfrom()  # May be None.
        if from_line is None:
            from_line = 'From MAILER-DAEMON %s' % time.asctime(time.gmtime())
        start = self._file.tell()
        self._file.write(from_line + os.linesep)
        self._dump_message(message, self._file, self._mangle_from_)
        stop = self._file.tell()
        return (start, stop)