title: Thread safety in python lists
body: <p>I have a list in a multithreaded program. The main thread adds elements to the list (using <code>list.append()</code>)&amp; deletes elements from a list (using <code>list.pop()</code>). The other threads checks for existence of particular elements in the list (using <code>if x in list</code>)</p>
  <p>No existing element in the list is ever modified (I am considering removal of elements as not a modification of an element).</p>
  <p>From python docs, it looks as if these operations are all thread safe &amp; I don't need to do any locking/unlocking myself. Am I correct in this assumption?</p>