python - How to get every first element in 2 dimensional list

Question

I have a list like this:

a = [[4.0, 4, 4.0], [3.0, 3, 3.6], [3.5, 6, 4.8]]

I want an outcome like this (EVERY first element in the list):

4.0, 3.0, 3.5

I tried a[::1][0], but it doesn't work

Answer 1

You can get the index [0] from each element in a list comprehension

>>> [i[0] for i in a]
[4.0, 3.0, 3.5]