Double iteration in list of tuples of tuples

Question

I would like to ask how can I get the same output but by applying a double list comprehension. Thank you.

a = [(('123',),('a',)),(('456',),('b',)),(('789',),('c',))]

b = [i[0] for i in a]

c = [i[0] for i in b]

output:

['123', '456', '789']

Answer 1

As suggested by @Ch3steR, adding @rassar's comment as answer.

Why not just [i[0][0] for i in a]? Or, if you really want a double list comprehension, [i[0] for i in [j[0] for j in a]].