title: How to check if subprocess has finished?
body: <p>I am starting a process by doing:</p>
  
  <pre><code>for i in range(1, processes + 1):
              hup = MyURLParser() //A class I made
              p = Process(target = hup.run)
              p.start()
  </code></pre>
  
  <p>After that, so that the main thread doesn't exit immediately I do:</p>
  
  <pre><code> while (True):
          print("Main sleeping...")
          sleep(20)
  </code></pre>
  
  <p>Instead of doing this, how can I check that each of the child processes are still running from the main thread ? Then instead of having the infinite loop I can break out of the loop at the right time and do something else....</p>