前端之家

  1. 首页
  2. 问答

Pyro4 [Errno -2]

• 问答

我正在尝试在PC和Raspberry Pi 4之间建立pyro4连接。
我PC上的代码是：

# saved as server.py
import Pyro4,Pyro4.naming
import socket,threading

# Define an object that will be accessible over the network.
# This is where all your code should go...
@Pyro4.expose
class MessageServer(object):
    def show_message(self,msg):
        print("Message received: {}".format(msg))


# Start a Pyro nameserver and daemon (server process) that are accessible
# over the network. This has security risks; see
# https://pyro4.readthedocs.io/en/stable/security.html
hostname = socket.gethostname()
ns_thread = threading.Thread(
    target=Pyro4.naming.startNSloop,kwargs={'host': hostname}
)
ns_thread.daemon = True   # automatically exit when main program finishes
ns_thread.start()
main_daemon = Pyro4.Daemon(host=hostname)

# find the name server
ns = Pyro4.locateNS()
# register the message server as a Pyro object
main_daemon_uri = main_daemon.register(MessageServer)
# register a name for the object in the name server
ns.register("example.message",main_daemon_uri)

# start the event loop of the main_daemon to wait for calls
print("Message server ready.")
main_daemon.requestLoop()

Raspberry上的代码是：

import Pyro4
import sys

print("Message:")
msg=sys.stdin.readline().strip()

message_server = Pyro4.Proxy("PYRONAME:192.168.1.5")
message_server.show_message(msg)

我PC上的代码没有显示任何错误，但是当我尝试从树莓派发送消息时，我得到了：

What s your message?
test
Traceback (most recent call last):
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/socketutil.py",line 102,in getIpAddress
    return getaddr(config.PREFER_IP_VERSION) if ipVersion is None else getaddr(ipVersion)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/socketutil.py",line 94,in getaddr
    ip = socket.getaddrinfo(hostname or socket.gethostname(),80,family,socket.SOCK_STREAM,socket.SOL_TCP)[0][4][0]
  File "/usr/lib/python3.7/socket.py",line 748,in getaddrinfo
    for res in _socket.getaddrinfo(host,port,type,proto,flags):
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception,another exception occurred:

Traceback (most recent call last):
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 515,in connect_and_handshake
    sslContext=sslContext)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/socketutil.py",line 266,in createSocket
    if getIpVersion(connect[0]) == 4:
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/socketutil.py",line 68,in getIpVersion
    address = getIpAddress(hostnameOrAddress)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/socketutil.py",line 106,in getIpAddress
    return getaddr(0)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/socketutil.py",flags):
socket.gaierror: [Errno -2] Name or service not known

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/pi/Desktop/client.py",line 10,in <module>
    message_server.show_message(msg)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 275,in __getattr__
    self._pyroGetMetadata()
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 615,in _pyroGetMetadata
    self.__pyroCreateConnection()
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 588,in __pyroCreateConnection
    uri = _resolve(self._pyroUri,self._pyroHmacKey)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 1915,in _resolve
    return nameserver.lookup(uri.object)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 596,in __pyroCreateConnection
    connect_and_handshake(conn)
  File "/home/pi/.local/lib/python3.7/site-packages/Pyro4/core.py",line 549,in connect_and_handshake
    raise ce
Pyro4.errors.CommunicationError: cannot connect to ('JAKOB-PC',9090): [Errno -2] Name or service not known

我的PC禁用了防火墙，因此应该没有任何问题。我的本地IP是192.168.1.5。 我正在使用无头的Raspberry，并使用puTTY和VNC在其上编写代码。

我已经用Google搜索了此错误，但找不到任何答案。任何帮助将不胜感激。

iCMS 回答：Pyro4 [Errno -2]

我做到了

#
# Server.py
#
from __future__ import print_function
import Pyro4


@Pyro4.expose
@Pyro4.behavior(instance_mode="single")
class Messenger(object):
    # This is a constructor
    def __init__(self):
        pass

    # This method will be called on the server
    def send_message(self,name,message):
        print("[{0}] {1}".format(name,message))


def main():
    Pyro4.Daemon.serveSimple(
        {
            Messenger: "example.messenger"
        },ns=True)


if __name__ == "__main__":
    main()

#
# Client.py
#

# This is the code that visits the warehouse.
import sys

import Pyro4
import Pyro4.util


sys.excepthook = Pyro4.util.excepthook

messenger = Pyro4.Proxy("PYRONAME:example.messenger@192.168.1.5")
messenger.send_message("Tim","Hello!")

然后跑

  • python -m Pyro4.naming -n 192.168.1.5
  • python Server.py
  • python Client.py
,

简而言之，我无法用Pyro解决问题，并且（几乎）没有人帮助，所以我决定改用'websockets'。

您可以阅读文档here，但无论如何我都会在这里进行解释。

首先，您需要两个具有网络连接的设备。您还必须在两者上都运行python 3.6.1。之后，如果尚未使用pip install websockets或我必须使用pip3 install websockets安装websocket，还需要安装websocket。

以下代码在服务器上运行，并处理您从客户端发送给它的消息。函数“ hello”是处理请求并发送回响应的简单示例。 “请求”是数据服务器接收的数据，该数据必须为字节，字符串为可迭代。响应是通过将请求转换为整数，将其平方后再转换回字符串来完成的。然后将此响应发送回客户端。 “ start_server”定义服务器，函数将定义其行为（hello），服务器在其上运行的女巫的IP地址（192.168.1.117），女巫上的端口将接收请求（8765）。

!/usr/bin/env python

import asyncio
import websockets

print("Running...")

async def hello(websocket,path):
    request = await websocket.recv()
    print("Request: " + request)

    response = str(int(request)*int(request))

    await websocket.send(response)
    print("Response:" + response)

start_server = websockets.serve(hello,"192.168.1.117",8765)

asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()

下一位是客户端上的代码。 “ uri”是服务器的IP地址和端口。函数“ tellServ”要求您输入一些数据（“ tell”变量）并将其发送到服务器。之后，它等待答复，一旦得到答复，它将打印出来。在这种情况下，如果我输入数字“ 6”，服务器将回答“ 36”。函数循环处于while循环中，因此我可以发送多个数字而不必重新启动脚本。

#!/usr/bin/env python

import asyncio
import websockets

uri = "ws://192.168.1.117:8765"

async def tellServ():
    async with websockets.connect(uri) as websocket:
        tell = input("Podatek ki ga posles: ")
        await websocket.send(tell)

        reply = await websocket.recv()
        print("Odgovor:")
        print(reply)
while 1:
    asyncio.get_event_loop().run_until_complete(tellServ())
pyro4raspberry-pi
本文链接：https://www.f2er.com/1917516.html

大家都在问