When i test an udp.py file on server and client in python34.


#!/usr/bin/env python
import socket, sys
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
MAX = 65535
PORT = 1060
if sys.argv[1:] == ['server']:
s.bind(('127.0.0.1', PORT))
print('Listening at', s.getsockname())
while True:
data, address = s.recvfrom(MAX)
print('The client at', address, 'says', repr(data))
s.sendto('Your data was %d bytes' % len(data), address)
elif sys.argv[1:] == ['client']:
print('Address before sending:',s.getsockname())
s.sendto('This is my message',('127.0.0.1', PORT))
print('Address after sending',s.getsockname())
data, address = s.recvfrom(MAX)
print('The server', address, 'says', repr(data))
else:
print('usage: udp_local.py server|client')


The command `python udp.py server` get output:
Listening at ('127.0.0.1', 1060)

Why `python udp.py client` run failure:

Traceback (most recent call last):
File "d://udp.py", line 15, in <module>
print('Address before sending:', s.getsockname())
OSError: [WinError 10022] An invalid argument was supplied
Hello,

According to http://stackoverflow.com/questions/15638214/socket-error-invalid-argument-supplied, the client socket doesn't have an address at time
when you call s.getsocketname. This raises an exception on Windows.

Removing the 'Address before sending' line will prevent the error.

As you're using Python3, you'll find that passing strings to s.sendto raises
a TypeError; you'll need to encode the strings as bytes.

Hope that helps,

Kev