Adding concurrency to my asyncio based file downlaoder script without hitting server [closed]

Question

Below is my code to download file as fast as possible using asycio Trying to implement, multiple server connection with multi chunk, multi threded downlad just like idm and aria2

import asyncio
import os.path
import shutil
import aiofiles

import aiohttp
import lxml.html as htmlparser
import cssselect
import regex, json
from tempfile import TemporaryDirectory

domain = "https://domain.com/"
url = 'https://domain.com/ust/xxxx'
CONTENT_ID = regex.compile(r"/ust/([^?#&/]+)")

def parts_generator(size, start=0, part_size=5 * 1024 ** 2):
    while size - start > part_size:
        yield start, start + part_size
        start += part_size
    yield start, size
    
async def main():
 async def download(url, headers, save_path):
        async with session.get(url, headers=headers) as request:
         file = await aiofiles.open(save_path, 'wb')
         await file.write(await request.content.read())
 
 async with aiohttp.ClientSession() as session:
  async with session.get(url) as first:
   cs = await first.text()
   csrf_token = htmlparser.fromstring(cs).cssselect("meta[name='csrf-token']")[0].get("content")
   content_id = CONTENT_ID.search(url).group(1)
   Headers={"x-requested-with": "XMLHttpRequest", "x-csrf-token": csrf_token}
   async with session.post(domain + "api/get&user=xxx&pass=yyy", headers=Headers, json={"id": content_id}) as resp:
       res = json.loads(await resp.text())
       re = res['result']['Original']['file']
   async with session.get(re) as request:
       size = request.content_length
       tasks = []
       file_parts = []
       filename = 'File.mp4'
       tmp_dir = TemporaryDirectory(prefix=filename, dir=os.path.abspath('.'))
       for number, sizes in enumerate(parts_generator(size)):
        part_file_name = os.path.join(tmp_dir.name, f'{filename}.part{number}')
        file_parts.append(part_file_name)
        tasks.append(await download(re, {'Range': f'bytes={sizes[0]}-{sizes[1]}'}, part_file_name))
       await asyncio.gather(*tasks)''
       with open(filename, 'wb') as wfd:
        for f in file_parts:
         with open(f, 'rb') as fd:
          shutil.copyfileobj(fd, wfd)
           
asyncio.run(main())

Can anyone help improvise it. is using asyncio better than threadpool and multiprocessing

my script still doesnt perform concurrent download

help with adding concurrency and handling cases where server repond with empty payload in casr of excessive request. ysing true loop to sleep and retry in such case

with idm this mp4 700mb can be downloaded within few minutes and idm can achive 3 mbps speed for this video download on my network

can someone help tweak my python script to achive same spped and failsafe downlaod like idm Also want to be able to play file simultaneiusly while downlaoding