如何用元组中每个元组的第一个值构成一个新元组？

Question

I want to form a tuple with the first elements of each tuple. Im a beginner in python, maybe this is an easy one but i cant find a way to do it plz help.

ex:

input

 x = (('A','B','C'),('D','E','F'),('G','H','I'))

output:

y= ('A', 'D', 'G')

Answer 1

x = (('A','B','C'),('D','E','F'),('G','H','I'))

for each in zip(*x):
    print(each)

prints:

('A', 'D', 'G')
('B', 'E', 'H')
('C', 'F', 'I')

Use the zip() function. Read more here.

Edited:

like CAB says if you just want the first one you can do:

y = zip(*x)[0] 

Answer 2

Use comprehension and convert to a tuple;

>>> x = (('A','B','C'),('D','E','F'),('G','H','I'))
>>> y = tuple([l[0] for l in x])
>>> y
('A', 'D', 'G')