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python3.5 asyncio协议

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我想 Build 一个聊天演示,但我无法收到服务器端发送的东西,除了第一次启动,有谁知道为什么?代码来自https://docs.python.org/3.4/library/asyncio-protocol.html#tcp-echo-client-protocol

Server.py

import asyncio

class EchoServerClientProtocol(asyncio.Protocol):
    def connection_made(self, transport):
        peername = transport.get_extra_info('peername')
        print('Connection from {}'.format(peername))
        self.transport = transport

    def data_received(self, data):
        message = data.decode()
        print('Data received: {!r}'.format(message))
        print('Send: {!r}'.format(message))
        self.transport.write(data)


loop = asyncio.get_event_loop()
# Each client connection will create a new protocol instance
coro = loop.create_server(EchoServerClientProtocol, '127.0.0.1', 8888)
server = loop.run_until_complete(coro)

# Serve requests until Ctrl+C is pressed
print('Serving on {}'.format(server.sockets[0].getsockname()))
try:
    loop.run_forever()
except KeyboardInterrupt:
    pass

# Close the server
server.close()
loop.run_until_complete(server.wait_closed())
loop.close()

Client.py

class EchoClientProtocol(asyncio.Protocol):
    def __init__(self, message, loop):
        self.message = message
        self.loop = loop
        self.transport = None

    def connection_made(self, transport):
        self.transport = transport

        transport.write(self.message.encode())
        print('Data sent: {!r}'.format(self.message))

        # while 1:
        #     message=input('please input the message:')
        #     transport.write(message.encode())
        #     print('Data sent: {!r}'.format(message))

    def data_received(self, data):
        # print('data_received')
        print('Data received: {!r}'.format(data.decode()))
        while 1:
            message = input('please input the message:')
            self.transport.write(message.encode())
            print('Data sent: {!r}'.format(message))

    def connection_lost(self, exc):
        print('The server closed the connection')
        print('Stop the event loop')
        self.loop.stop()

loop = asyncio.get_event_loop()
message = 'Hello World!'
coro = loop.create_connection(lambda: EchoClientProtocol(message, loop),
                              '127.0.0.1', 8888)
loop.run_until_complete(coro)
loop.run_forever()
loop.close()

结果显示:无法显示'Data received: ' ##### ' like ' def data_received(self,data)'仅用于任何人有解决方案吗? [结果] [1] [1]:https://i.stack.imgur.com/IoqA9.png

1 回答

  • 0

    您从 EchoClientProtocol.data_received() 创建了所谓的阻止功能 . 只有当事件循环可以处理它但阻塞功能阻止它时,来自服务器的每个传递的消息都可以传递到 EchoClientProtocol.data_received() .

    这段代码

    while 1: # More Pythonic way is While True
        message = input('please input the message:')
        self.transport.write(message.encode())
    

    从用户那里获取消息并将其发送到服务器,直到这一刻它一切正常 . 在下一步中,它会启动另一个循环,但代码永远不会进入事件循环(因此无法处理传入的消息) .

    您可以像这样编辑客户端代码:

    def data_received(self, data):
            print('Data received: {!r}'.format(data.decode()))
            message = input('please input the message:')
            self.transport.write(message.encode())
    

    当您从服务器收到 Hello World! 时,首先调用 data_received 客户端(它是从 connection_made 发送的 Hello World! ) . 现在处理如下:

    • 打印收到的消息(在第一次调用中是 Hello World!

    • 从用户那里获取新消息

    • 将其发送到服务器

    • 该函数返回并且控件被赋予事件循环 .

    • 服务器收到新消息并将其发送回客户端

    • 客户端调用 data_received 上的事件循环

    • 转到步骤1

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