code: def find_ws_name(wb, name):
      
      if isinstance(wb, string_types):
          # FIXME: importar o borrar segun corresponda
          wb = load_workbook(wb, read_only=True, data_only=True)
  
      for sheetname in wb.sheetnames:
          if sheetname.lower() == name.lower():
              return sheetname
  
      raise Exception("No existe la hoja {}".format(name))
docs: Busca una hoja en un workbook sin importar mayúsculas/minúsculas.