title: How to Iterate over Alphabets in Python
body: <p>Lets suppose a=0,b=1....,z=25,aa=26,...and so on.</p>
  
  <p>How do I form a list in python to find the index for any given alphabet suppose ey?</p>
  
  <pre><code>book = xlrd.open_workbook(input("Enter name of the excel file "))
  table_list=list(book.sheet_names())
  print("the sheets in the excel file are :")
  for name in table_list:
       print(name)
  first_sheet = book.sheet_by_index(table_list.index(input("Enter sheet name ")))
  
  arrayofvalues = first_sheet.col_values(152,2,239)
  </code></pre>
  
  <p>I need to use the obtained value in the col_val function.</p>
  
  <p>Is there any other method?</p>