Basic tcp portscan script.

portscan.py

import socket
import threading
from queue import Queue

def is_open(host, port):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(0.5)
    try:
        s.connect((host, port))
        s.close()
        return True
    except socket.error:
        return False

num_worker_threads = 100
mtx = threading.Lock()

def scan(host):
    q = Queue()
    for p in range(1, 25000):
        q.put(p)
        
    def work():
        while not q.empty():
            p = q.get()
            if is_open(host, p):
                mtx.acquire()
                print(p, "open")
                mtx.release()
            q.task_done()

    for i in range(num_worker_threads):
        t = threading.Thread(target=work)
        t.daemon = True
        t.start()

    q.join()