review of tag answer system

class CliHandler(RpcHandler):

    '''Handle RPC incoming request'''

    @pure

    def get_tags(self, tags=None, resolve=True):

        if tags is None:

            tags = ( "version" )

        if "version" in tags:

            return { "version": { "value": cccli.version, "ttl": -1 } }

    @pure

    def quit(self, rpc=None):

        Printer().fatal("Disconnected from server!")

    @pure

    def get_tags(self, tags=None, resolve=False):

        if tags is None:

            tags = [ x[8:] for x in dir(self) if x.startswith("get_tag_") ]

        d = dict()

        for t in tags:

            method = "get_tag_%s"%t

            if hasattr(self, method):

                d[t] = getattr(self, method)(resolve)

        return d

    def get_tag_version(self, resolve):

        '''Return tag version'''

        return { "value": cccli.version, "ttl": -1 }

    def get_tag_uname(self, resolve):

        '''Return value of tag uname'''

        if resolve:

            try:

                p = subprocess.Popen(["uname", "-a"], close_fds=True, shell=False, stdout=subprocess.PIPE)

                return  { "value": p.stdout.read().rstrip("\n")  , "ttl": -1 }

            except Exception:

                return { "value": "", "ttl": -1 }

        else:

            return { "ttl": -1 }