title: Do I need a lock for multithreaded access of size of list in Python?
body: <p>I have got a list shared by multiple threads. I am using a lock for adding or removing items from the list. </p>
  
  <p>I have got another thread who only needs to get the length of the list, do I need to use a lock also for that thread?</p>
  
  <p>My posed this question because for instance with files you can read from multiple threads without locks and you need them only when writing to them.</p>
  
  <p>Additional details: I am using Python 3.6.4</p>