title: Dictionary update method. Python 3.4
body: <p>Want to know why that function doesn't work ?</p>
  
  <pre><code>students = {'dsd': 13}
  
  student1 = {'dsdsd': 15}
  
  print(students.update(student1))
  </code></pre>
  
  <p>After printing it just brings out <code>None</code> in console.</p>