FTP_SERVFER

import socket
import os,sys

ss=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
ss.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
addr=('localhost',4444)
ss.bind(addr)
ss.listen(5)

def main():
    while True:
        try:
            print("Server waiting for connection ..")
            cs,c_addr=ss.accept()
            print("Client connected from:",c_addr)
            file_name=cs.recv(1024).decode()
            if os.path.exists(file_name):
                print("File is in server sending it to client.")

                file=open(file_name,'rb')
                while True:
                    data=file.read(4096)
                    if not data:
                        break
                    cs.send(data)
                    print("Sending...",end="\r")

                print("Sent.")
                cs.close()
            else:
                print("Receiving file:%s"%file_name)
                #input("Do you want to download it? Press Return to continue or CTRL-D to exit.")
                rcv_file=open(file_name,'wb')

                while True:
                    data=cs.recv(4096)
                    if not data:
                        break
                    print("Receiving...",end="\r")
                    rcv_file.write(data)

                print("\nRecived")
                cs.close()
        except KeyboardInterrupt:
            ss.close()
            sys.exit(1)

    ss.close()

main()