Add numbers from excel sheet

def add_from_sheet(sheet, start_row, end_row):
  total = 0
  start_row = start_row - 1
  end_row = end_row - 1
  for row_num in range(start_row, end_row):
      total = total + sheet.cell(row=row_num, column=1).value
  return total
    
add_from_sheet(ws, 2, 4)