title: Get absolute path of caller file
body: <p>Say I have two files in different directories: <code>1.py</code> (say, in <code>C:/FIRST_FOLDER/1.py</code>) and <code>2.py</code> (say, in <code>C:/SECOND_FOLDER/2.py</code>).</p>
  
  <p>The file <code>1.py</code> imports <code>2.py</code> (using <code>sys.path.insert(0, #path_of_2.py)</code> followed, obviously, by <code>import 2</code>) and calls one of the functions in <code>2.py</code>, the function it calls needs to know the absolute path of <code>1.py</code> (it looks for a file in that same directory).</p>
  
  <p>I know there's <code>inspect.stack()[1]</code> but this only returns the file name and not the path.</p>
  
  <p>Any idea on how to implement this?</p>