title: python: get full formula from excel, using xlrd
body: <p>I'm trying to get the full formula from Excel file
  I tried many ways, but all get for me the value</p>
  
  <p>I need the full formula that is in the cell, not the value itself</p>
  
  <p>I'm using python with xlrd</p>
  
  <p>is there any function I can use ? 
  or is there anyway to ?</p>
  
  <p>Thanks alot</p>