title: Get Worksheet index from title or instance using Openpyxl
body: <p>How can someone get the Worksheet's index number using a Worksheet's property with Openpyxl?</p>
  
  <p>The best example would be an Excel workbook that contains 3 sheets: "<code>Aaa</code>", "<code>Bbb</code>" and "<code>Ccc</code>". Knowing the title <code>"Bbb"</code>, what would be the way of getting the index number of that sheet?</p>