UDP socket programming python 3.5 - Client not receiving servers data -

i'm having trouble socket programs in python. i'm trying send byte string client program. server seems sending data, client isn't receiving it. won't post code lengthy programs, here i'm using send data (seems working):

server.sendto(packed_data, (host, port)) 

and here client program:

readable, writeable, error = select.select([server], [], [], 1)      if readable: # ensure can read socket          data, addr = server.recvfrom(1024)         print(data.decode('utf8')) # convert string  

the server socket not readable times out.