how to convert a list of tuples into a lists of part of tuples in python

Question

I want to convert

 l = [(1, 'a'), (2, 'b')]

to

 r = [1, 2]
 p = ['a', 'b']

Obviously, looping can be used. is it possible to use lambda? Any other ways

Thanks David

Answer 1

Use zip with * :

>>> l = [(1, 'a'), (2, 'b')]
>>> r, p = zip(*l)
>>> r
(1, 2)
>>> p
('a', 'b')

Answer 2

You have to use list conprehension and create new variable.

>>> a = [x[0] for x in l]
>>> a
[1, 2]
>>> p = [x[1] for x in l]
>>> p
['a', 'b']