python调用ryu库

要使用Python调用Ryu库，您需要首先安装Ryu。您可以通过以下命令在终端中安装Ryu：

pip install ryu

然后，在您的Python脚本中导入Ryu库并使用它。例如，以下是一个简单的Ryu应用程序示例：

from ryu.base import app_manager
from ryu.controller import ofp_event
from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.ofproto import ofproto_v1_0

class SimpleSwitch(app_manager.RyuApp):
    OFP_VERSIONS = [ofproto_v1_0.OFP_VERSION]

    def __init__(self, *args, **kwargs):
        super(SimpleSwitch, self).__init__(*args, **kwargs)

    @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
    def switch_features_handler(self, ev):
        datapath = ev.msg.datapath
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        match = parser.OFPMatch()
        actions = [parser.OFPActionOutput(ofproto.OFPP_FLOOD)]
        inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS, actions)]
        mod = parser.OFPFlowMod(datapath=datapath, priority=0, match=match, instructions=inst)
        datapath.send_msg(mod)

    @set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
    def packet_in_handler(self, ev):
        msg = ev.msg
        datapath = msg.datapath
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        actions = [parser.OFPActionOutput(ofproto.OFPP_FLOOD)]
        out = parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id, in_port=msg.match['in_port'], actions=actions)
        datapath.send_msg(out)

此示例应用程序是一个简单的交换机，它将所有传入的数据包洪泛到所有端口。您可以通过以下方式运行此应用程序：

ryu-manager simple_switch.py

这将启动Ryu控制器并加载您的应用程序。现在，您可以通过连接到交换机并发送数据包来测试应用程序的功能。