title: UDP socket sendto() functions
body: <p>I get an error if I want to write on my udp socket like this.
  According to the docu there shouldn't be a problem.
  I don't understand why bind() works well in the same way but sendto() fails. </p>
  
  <pre><code>udp_port = 14550
  udp_server  = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  udp_server.bind(('127.0.0.1', udp_port))
  udp_clients = {}
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>udp_server.sendto('', ('192.0.0.1', 14550) )
  socket.error: [Errno 22] Invalid argument
  </code></pre>