title: when doing downloading with python,should I use multithreading or multiprocessing?
body: <p>Recently I'm working on a program which can download manga from a online manga website.It works but a bit slow.So I decide to use multithreading/processing to speed up downloading.Here are my questions:</p>
  
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  <li><p>which one is better?(this is a python3 program)</p></li>
  <li><p>multiprocessing,I think,will definitely work.If I use multiprocessing,what is the suitable amount of processes?Does it relate to the number of cores in my CPU?</p></li>
  <li><p>multithreading will probably work.This download work obviously needs much time to wait for pics to be downloaded,so I think when a thread starts waiting,python will make another thread work.Am I correct?<br>
  I've read 《<a href="http://www.dabeaz.com/python/NewGIL.pdf" rel="nofollow">Inside the New GIL</a>》by David M.Beazley.What's the influence of GIL if I use multithreading? </p></li>
  </ol>