20220320-day9:enumerate替换len方法显示索引

原来的实现方法：

data_list = [11, 22, 33, 44, 55]
for index in range(len(data_list)):
    print(index+1, data_list[index])

新的实现方法：

data_list = [11, 22, 33, 44, 55]
for i, item in enumerate(data_list, 1):
    print(i, item)