Transfer Files in the Network using Sockets in Python

#   sender.py
import socket
import tqdm
import os
import argparse
SEPARATOR = "<SEPARATOR>"
BUFFER_SIZE = 1024 * 4
def send_file(filename, host, port):
    filesize = os.path.getsize(filename)
    s = socket.socket()
    print(f"[+] Connecting to {host}:{port}")
    s.connect((host, port))
    print("[+] Connected.")
    s.send(f"{filename}{SEPARATOR}{filesize}".encode())
    progress = tqdm.tqdm(range(filesize), f"Sending {filename}", unit="B", unit_scale=True, unit_divisor=1024)
    with open(filename, "rb") as f:
        for _ in progress:
            bytes_read = f.read(BUFFER_SIZE)
            if not bytes_read:
                break
            s.sendall(bytes_read)
            progress.update(len(bytes_read))
    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
import socket
import tqdm
import os
while True:
    SERVER_HOST = "0.0.0.0"
    SERVER_PORT = 5001
    BUFFER_SIZE = 4096
    SEPARATOR = "<SEPARATOR>"
    s = socket.socket()
    s.bind((SERVER_HOST, SERVER_PORT))
    s.listen(5)
    print(f"[*] Listening as {SERVER_HOST}:{SERVER_PORT}")
    client_socket, address = s.accept() 
    print(f"[+] {address} is connected.")
    received = client_socket.recv(BUFFER_SIZE).decode()
    filename, filesize = received.split(SEPARATOR)
    filename = os.path.basename(filename)
    filesize = int(filesize)
    progress = tqdm.tqdm(range(filesize), f"Receiving {filename}", unit="B", unit_scale=True, unit_divisor=1024)
    with open(filename, "wb") as f:
        for _ in progress:
            bytes_read = client_socket.recv(BUFFER_SIZE)
            if not bytes_read:    
                break
            f.write(bytes_read)
            progress.update(len(bytes_read))
    client_socket.close()
    s.close()