title: Loop over a loop
body: <p>So far I have gotten my code to loop through five different rows on an excel sheet successfully. I not need it to do this same thing for twelve different sheets. I'm pretty new to python and attempted to put a for loop right on top of my previous for loop, with no success. Here is a snippet of the for loops I am using:</p>
  
  <pre><code> sheetnames = ['0h UV Exposure, Roll Direction', 
            '4h UV Exposure, Roll Direction', 
            '8h UV Exposure, Roll Direction', 
            '12h UV Exposure, Roll Direction', 
            '18h UV Exposure, Roll Direction', 
            '24h UV Exposure, Roll Direction', 
            '36h UV Exposure, Roll Direction', 
            '48h UV Exposure, Roll Direction', 
            '68h UV Exposure, Roll Direction', 
            '78h UV Exposure, Roll Direction', 
            '82h UV Exposure, Roll Direction', 
            '96h UV Exposure, Roll Direction'] 
  
   samplenums = [1,2,3,4,5]
  
   for sheet in sheetnames:
       for dataset in samplenums:
           data = get_data(sheetnames[sheet],dataset)
  </code></pre>