How to fix multithreaded script error in python?

Question

Python

There is a script:

from concurrent.futures import ThreadPoolExecutor, Future, TimeoutError
from urllib.parse import urlparse
from threading import RLock
import threading
import requests
import urllib3
import time

urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
lock = threading.Lock()

with open('lists/0.txt') as lines:
    domains = iter(['http://' + line.strip() for line in lines])

db = set()
def worker(domain):
    try:
        r = requests.head(domain, verify=False, allow_redirects=True, timeout=3)
        parsed_uri = urlparse(r.url)
        if parsed_uri.netloc.startswith('www.'):
            parsed_domain = '{uri.scheme}://{}'.format(parsed_uri.netloc[4:], uri=parsed_uri)
        else:
            parsed_domain = '{uri.scheme}://{uri.netloc}'.format(uri=parsed_uri)
        tmp_domain = '{uri.netloc}'.format(uri=parsed_uri)
        r.raise_for_status()
    except (requests.exceptions.ConnectionError, requests.exceptions.HTTPError, requests.exceptions.TooManyRedirects, requests.exceptions.Timeout):
        if tmp_domain not in db:
            with lock:
                with open('error.txt', 'a') as f:
                    f.write(parsed_domain + '\n')
                db.add(tmp_domain)
        return
    except:
        if tmp_domain not in db:
            with lock:
                with open('unknow.txt', 'a') as f:
                    f.write(parsed_domain + '\n')
                db.add(tmp_domain)
        return
    
    if tmp_domain not in db:
        with lock:
            with open('good.txt', 'a') as f:
                f.write(parsed_domain + '\n')
            db.add(tmp_domain)

def task_queue(task, iterator, concurrency=10):
    def submit():
        try:
            with lock:
                obj = next(iterator)
        except StopIteration:
            return

        stats['delayed'] += 1
        future = executor.submit(task, obj)
        future.add_done_callback(upload_done)

    def upload_done(future):
        with io_lock:
            submit()
            stats['delayed'] -= 1
            stats['done'] += 1

    io_lock = RLock()
    executor = ThreadPoolExecutor(concurrency)
    stats = {'done': 0, 'delayed': 0}

    for _ in range(concurrency):
        submit()

    return stats

stats = task_queue(worker, domains, concurrency=150)
while True:
    #print('\rdone {done}, in work: {delayed}  '.format(**stats))
    if stats['delayed'] == 0:
        break
    time.sleep(0.2)

The code works, but it seems to me that it misses positive responses. Please tell me how to fix.