title: What is the advantage of following Inheritance
body: <p>I frequently read code of the libraries</p>
  
  <p>I have come across the following code snippets.
  The code snippets are from the python schedule library</p>
  
  <p>I have searched internet but haven't found satisfactory answers</p>
  
  <pre><code>class ScheduleError(Exception):
      """Base schedule exception"""
      pass
  
  
  class ScheduleValueError(ScheduleError):
      """Base schedule value error"""
      pass
  
  
  class IntervalError(ScheduleValueError):
      """An improper interval was used"""
      pass
  </code></pre>
  
  <p>I would like to know what is the advantage of inheriting from a class which has no attributes or methods in it</p>
  
  <p>I can benefit from both theoretical and practical explantions</p>