I want to duplicate a list in a list of list with header. The list of list is coming from a list =[pandas.read_excel(file, header=['a','b']) for file in files] to read multiple excel files.

So I have list = [[first_list], [second_list], [third_list], ...] All the lists have the same header.

I want to duplicate the second list (and only this one) to have :

list = [[first_list], [second_list], [second_list], [third_list], ...] 

What is the best way to do it ?

CodePudding user response：

If you have a list with at least 2 elements called my_list, you can do:

my_list.insert(2, my_list[1])