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我学习python 3，是我的第一语言，所以很抱歉，如果这是一个愚蠢的问题，但我不知道为什么它doesn没有工作... 我正在测试一个简单的回声客户端/服务器应用程序。根据我的书，我首先创建了一个名为tincanchat文件：NameError与回声客户端/服务器测试：客户端无法发送自定义消息到服务器
import socket
HOST = ''
PORT = 4040
def create_listen_socket(host, port):
""" Setup the sockets our server will receive connection
requests on """
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind((host, port))
sock.listen(100)
return sock
def recv_msg(sock):
""" Wait for data to arrive on the socket, then parse into
messages using b'\0' as message delimiter """
data = bytearray()
msg = ''
# Repeatedly read 4096 bytes off the socket, storing the bytes
# in data until we see a delimiter
while not msg:
recvd = sock.recv(4096)
if not recvd:
# Socket has been closed prematurely
raise ConnectionError()
data = data + recvd
if b'\0' in recvd:
# we know from our protocol rules that we only send
# one message per connection, so b'\0' will always be
# the last character
msg = data.rstrip(b'\0')
msg = msg.decode('utf-8')
return msg
def prep_msg(msg):
""" Prepare a string to be sent as a message """
msg += '\0'
return msg.encode('utf-8')
def send_msg(sock, msg):
""" Send a string over a socket, preparing it first """
data = prep_msg(msg)
sock.sendall(data)
然后，我写的服务器：
import tincanchat
HOST = tincanchat.HOST
PORT = tincanchat.PORT
def handle_client(sock, addr):
""" Receive data from the client via sock and echo it back """
try:
msg = tincanchat.recv_msg(sock) # Blocks until received
# complete message
print('{}: {}'.format(addr, msg))
tincanchat.send_msg(sock, msg) # Blocks until sent
except (ConnectionError, BrokenPipeError):
print('Socket error')
finally:
print('Closed connection to {}'.format(addr))
sock.close()
if __name__ == '__main__':
listen_sock = tincanchat.create_listen_socket(HOST, PORT)
addr = listen_sock.getsockname()
print('Listening on {}'.format(addr))
while True:
client_sock, addr = listen_sock.accept()
print('Connection from {}'.format(addr))
handle_client(client_sock, addr)
而且客户端：
import sys, socket
import tincanchat
HOST = sys.argv[-1] if len(sys.argv) > 1 else '127.0.0.1'
PORT = tincanchat.PORT
if __name__ == '__main__':
while True:
try:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((HOST, PORT))
print('\nConnected to {}:{}'.format(HOST, PORT))
print("Type message, enter to send, 'q' to quit")
msg = input()
if msg == 'q': break
tincanchat.send_msg(sock, msg) # Blocks until sent
print('Sent message: {}'.format(msg))
msg = tincanchat.recv_msg(sock) # Block until
# received complete
# message
print('Received echo: ' + msg)
except ConnectionError:
print('Socket error')
break
finally:
sock.close()
print('Closed connection to server\n')
我运行服务器，然后是与服务器连接并要求输入的客户端。此时，它返回此错误：
Connected to 127.0.0.1:4040
Type message, enter to send, 'q' to quit
Hello
Closed connection to server
Traceback (most recent call last):
File "C:\xxxxxxxxx\1.2-echo_client-uni.py", line 22, in <module>
except ConnectionError:
NameError: name 'ConnectionError' is not defined
问题在哪里？ 在此先感谢:)