openpyxl convert CSV to EXCEL

How can I convert a CSV file with : delimiter to XLS (Excel sheet) using openpyxl module?

import csv
from openpyxl import Workbook
from openpyxl.cell import get_column_letter

f = open(r'C:\Users\Asus\Desktop\herp.csv')

csv.register_dialect('colons', delimiter=':')

reader = csv.reader(f, dialect='colons')

wb = Workbook()
dest_filename = r"C:\Users\Asus\Desktop\herp.xlsx"

ws = wb.worksheets[0]
ws.title = "A Snazzy Title"

for row_index, row in enumerate(reader):
    for column_index, cell in enumerate(row):
        column_letter = get_column_letter((column_index + 1))
        ws.cell('%s%s'%(column_letter, (row_index + 1))).value = cell

wb.save(filename = dest_filename)