Add item to list of lists?

Question

Python

There is a list of lists construct

l = 

It is necessary to insert into each internal list at the first position a string formed from the first element of the list minus the WW_ part.

result = [items.insert(0, items[0].split('WW_')[1]) for items in l]

print(result)
Expected Result

The received result What not so I do?
[None, None, None]

Answer 1

newArr = [ [ n[0].split('_')[1], *n ] for n in arr ]