title: Python - index in enumerate
body: <p>I am just starting to learn Python. At what index value in python does a <code>for</code> loop start from? </p>
  
  <p>For example, if I have a text file with 390 lines, and I iterate:</p>
  
  <p><code>for i, word in enumerate(f)</code></p>
  
  <p>Does the value of the index start from <code>0</code> or from <code>1</code>? 
  Also, if I want to print out every 30th line in the file, then will I have to iterate like this?</p>
  
  <pre><code>if i+1 in [30,60,90,120,150,180,210,240,270,300,330,360,390]:
      print i
      ...
  </code></pre>