title: NameError, python3 get_step not defined
body: <p>I'm following the book "Python crash Course" and i keep getting this </p>
  
  <blockquote>
    <p>NameError: name 'get_step' is not defined</p>
  </blockquote>
  
  <p>It's in python3 and both files are in the same directory.</p>
  
  <p>So..the function is defined inside this class: </p>
  
  <p><img src="https://i.stack.imgur.com/mdfW6.png" alt="random_walk.py"></p>
  
  <p>and the class is imported to:</p>
  
  <p><img src="https://i.stack.imgur.com/AXZZD.png" alt="main_program"></p>
  
  <p>where it calls fill_walks, and fill_walks calls get_step. What am i missing here? can someone help me please</p>