title: Find all possible stacktraces for a function
body: <p>First of all, I'm not sure I'm asking for something that is doable.<br>
  Sometimes, when I have to do some refactoring in a large codebase, I need to change the output or even the signature of a certain function. Before than I do that, I have to make sure that that output is handled correctly by the other functions that are going to call it.<br>
  The way I do it is by searching for the function name, say <code>get_timezone_from user</code> and then I see that function is used by two other functions called <code>format</code> and <code>change_timezone_for_user</code>. And I start looking for where those two functions are used etc... until I end up with a graph where each path looks like a stacktrace.</p>
  
  <p>There are two problems.<br>
  The first one is that doing this manually is pretty time consuming.<br>
  The second is that when I look at all occurrences of a function name like <code>format</code>, I will often find occurences of the word <code>format</code> in different contexts. It can be a comment or even another function defined somewhere else.</p>
  
  <p>My question is simple:<br>
  Is there an IDE or a tool that allows to find where in your code a certain function is called? Even better would be if that tool is recursive so that it draws the whole graph.</p>
  
  <p>I'm trying to achieve this in Python if that helps.</p>