Python: List comprehension list of lists

Question

I have a list of lists, and would like to use list comprehension to apply a function to each element in the list of lists, but when I do this, I end up with one long list ra

Answer 1

Use this:

[[number+1 for number in group] for group in x]

Or use this if you know map:

[map(lambda x:x+1 ,group) for group in x]

Answer 2

lista = [[i+3*(j-1) for i in range(1,4)] for j in range(1,4)]

print(lista)
# outputs [[1, 2, 3], [4, 5, 6], [7, 8, 9]]