nntplib.py 文件源码

def login(self, user=None, password=None, usenetrc=True):
        if self.authenticated:
            raise ValueError("Already logged in.")
        if not user and not usenetrc:
            raise ValueError(
                "At least one of `user` and `usenetrc` must be specified")
        # If no login/password was specified but netrc was requested,
        # try to get them from ~/.netrc
        # Presume that if .netrc has an entry, NNRP authentication is required.
        try:
            if usenetrc and not user:
                import netrc
                credentials = netrc.netrc()
                auth = credentials.authenticators(self.host)
                if auth:
                    user = auth[0]
                    password = auth[2]
        except IOError:
            pass
        # Perform NNTP authentication if needed.
        if not user:
            return
        resp = self._shortcmd('authinfo user ' + user)
        if resp.startswith('381'):
            if not password:
                raise NNTPReplyError(resp)
            else:
                resp = self._shortcmd('authinfo pass ' + password)
                if not resp.startswith('281'):
                    raise NNTPPermanentError(resp)
        # Capabilities might have changed after login
        self._caps = None
        self.getcapabilities()
        # Attempt to send mode reader if it was requested after login.
        # Only do so if we're not in reader mode already.
        if self.readermode_afterauth and 'READER' not in self._caps:
            self._setreadermode()
            # Capabilities might have changed after MODE READER
            self._caps = None
            self.getcapabilities()