sender.py

from socket import *
import sys

s = socket(AF_INET,SOCK_DGRAM)
host = raw_input("Enter host address:  ")
port = 9999
buf =1024
addr = (host,port)

file_name= raw_input("Enter file name:  ")

s.sendto(file_name,addr)

f=open(file_name,"rb")
data = f.read(buf)
while (data):
    if(s.sendto(data,addr)):
        print "Sending ..."
        data = f.read(buf)
s.close()
f.close()