Code for How to Transfer Files in the Network using Sockets in Python Tutorial

sender.py

"""
Client that sends the file (uploads)
"""
import socket
import tqdm
import os
import argparse

SEPARATOR = "<SEPARATOR>"
BUFFER_SIZE = 1024 * 4 #4KB

def send_file(filename, host, port):
    # get the file size
    filesize = os.path.getsize(filename)
    # create the client socket
    s = socket.socket()
    print(f"[+] Connecting to {host}:{port}")
    s.connect((host, port))
    print("[+] Connected.")

    # send the filename and filesize
    s.send(f"{filename}{SEPARATOR}{filesize}".encode())

    # start sending the file
    progress = tqdm.tqdm(range(filesize), f"Sending {filename}", unit="B", unit_scale=True, unit_divisor=1024)
    with open(filename, "rb") as f:
        while True:
            # read the bytes from the file
            bytes_read = f.read(BUFFER_SIZE)
            if not bytes_read:
                # file transmitting is done
                break
            # we use sendall to assure transimission in 
            # busy networks
            s.sendall(bytes_read)
            # update the progress bar
            progress.update(len(bytes_read))

    # close the socket
    s.close()

if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser(description="Simple File Sender")
    parser.add_argument("file", help="File name to send")
    parser.add_argument("host", help="The host/IP address of the receiver")
    parser.add_argument("-p", "--port", help="Port to use, default is 5001", default=5001)
    args = parser.parse_args()
    filename = args.file
    host = args.host
    port = args.port
    send_file(filename, host, port)

receiver.py

"""
Server receiver of the file
"""
import socket
import tqdm
import os

# device's IP address
SERVER_HOST = "0.0.0.0"
SERVER_PORT = 5001
# receive 4096 bytes each time
BUFFER_SIZE = 4096
SEPARATOR = "<SEPARATOR>"
# create the server socket
# TCP socket
s = socket.socket()
# bind the socket to our local address
s.bind((SERVER_HOST, SERVER_PORT))
# enabling our server to accept connections
# 5 here is the number of unaccepted connections that
# the system will allow before refusing new connections
s.listen(5)
print(f"[*] Listening as {SERVER_HOST}:{SERVER_PORT}")
# accept connection if there is any
client_socket, address = s.accept() 
# if below code is executed, that means the sender is connected
print(f"[+] {address} is connected.")

# receive the file infos
# receive using client socket, not server socket
received = client_socket.recv(BUFFER_SIZE).decode()
filename, filesize = received.split(SEPARATOR)
# remove absolute path if there is
filename = os.path.basename(filename)
# convert to integer
filesize = int(filesize)
# start receiving the file from the socket
# and writing to the file stream
progress = tqdm.tqdm(range(filesize), f"Receiving {filename}", unit="B", unit_scale=True, unit_divisor=1024)
with open(filename, "wb") as f:
    while True:
        # read 1024 bytes from the socket (receive)
        bytes_read = client_socket.recv(BUFFER_SIZE)
        if not bytes_read:    
            # nothing is received
            # file transmitting is done
            break
        # write to the file the bytes we just received
        f.write(bytes_read)
        # update the progress bar
        progress.update(len(bytes_read))

# close the client socket
client_socket.close()
# close the server socket
s.close()