How to make a list with elements to list with list with only one element?

Question

I have a list with n elements but i would like to convert it to a list which contains n list, and every list contains a single element.

 a = ['1','2','3','4']
 b = [['1'],['2'],['3'],['4']]

How can I make from a to b?

Answer 1

You can try list comprehension

b = [[i] for i in a]