title: Exercises 3.3 from Think Python
body: <p><strong>Problem:</strong> 
  Python provides a built-in function called <strong>len</strong> that returns the length of a string, so the value of len('allen') is 5.
  Write a function named <strong>right_justify</strong> that takes a string named <strong>s</strong> as a parameter and prints the string with enough leading spaces so that the last letter of the string is in column 70 of the display. </p>
  
  <pre><code>&gt;&gt;&gt; right_justify('allen')
                                                                  allen
  </code></pre>
  
  <p>I tried writing some codes as follows:   </p>
  
  <pre><code>&gt;&gt;&gt; def right_justify(s):
  ...     print                                                   s
  ...     
  &gt;&gt;&gt; right_justify('allen')
  &gt;&gt;&gt; allen  
  </code></pre>
  
  <p>The result is without enough leading spaces required by the exercise. And I couldn't use the built-in function <strong>len</strong> to help solve it either.</p>
  
  <p>Any idea on how to resolve this problem?</p>