Extract first item of each sublist

konrad picture konrad · Jul 31, 2014 · Viewed 286.6k times · Source

I am wondering what is the best way to extract the first item of each sublist in a list of lists and append it to a new list. So if I have:

lst = [[a,b,c], [1,2,3], [x,y,z]]

and I want to pull out a, 1 and x and create a separate list from those.

I tried:

lst2.append(x[0] for x in lst)

Answer

alecxe picture alecxe · Jul 31, 2014

Using list comprehension:

>>> lst = [['a','b','c'], [1,2,3], ['x','y','z']]
>>> lst2 = [item[0] for item in lst]
>>> lst2
['a', 1, 'x']