Simple python port scanner

main.py

from multiprocessing import Process
import argparse
import socket
import time
import math


def is_port_open(ip_address, port, timeout=1):
    try:
        socket.create_connection((ip_address, port), timeout).close()
        return True
    except ConnectionRefusedError:
        return False


def scan_ip_address(ip_address, start_port, end_port):
    for port in range(start_port, end_port):
        if is_port_open(ip_address, port):
            print(f"port {port} is open!")


def scan_host(hostname, start_port, end_port, workers_count):
    ip_address = socket.gethostbyname(hostname)

    print(f"scanning hostname {hostname}")
    print(f"ip address: {ip_address}")

    step = math.ceil((end_port - start_port + 1) / workers_count)
    processes = []

    for port in range(start_port, end_port + 1, step):
        fun_args = (ip_address, port, min(port + step - 1, end_port))
        process = Process(target=scan_ip_address, args=fun_args)
        process.start()
        processes.append(process)

    for process in processes:
        process.join()


if __name__ == "__main__":
    arg_parser = argparse.ArgumentParser()
    arg_parser.add_argument("--hostname", type=str)
    arg_parser.add_argument("--start-port", type=int, default=1)
    arg_parser.add_argument("--end-port", type=int, default=65535)
    arg_parser.add_argument("--workers", type=int)

    args = arg_parser.parse_args()

    start_time = time.time()
    scan_host(args.hostname, args.start_port, args.end_port, args.workers)
    end_time = time.time()

    print(f"elapsed time: {round(end_time - start_time)} seconds")