title: Generate numbers with 3 digits
body: <p>I wanted to generate numbers starting from 000 to 120 in sequence.
  I know you can generate numbers from 0 to 120 by using a loop.But I want all the numbers to have 3 digits.</p>
  
  <p>The output should be</p>
  
  <pre><code>000
  001
  002 
  ...
  ...
  120
  </code></pre>
  
  <p>Instead of </p>
  
  <pre><code>0
  1
  2
  ...
  ...
  120
  </code></pre>
  
  <p>Is there any easy way to achieve this in python or should I be making separate code for <code>0-9</code> <code>10-99</code> and <code>100-120</code> ?</p>