How to make a list of certain items from a different list

Question

For example: list1 = [1t, 1r, 2t, 2r, 3t, 3r...., nt, nr]. How do I make a list list_t that has all t items from list1? I tried using the following for loop:

for i in list1[0:]:
    list_t =[i.t]

But this only assigns the first item to list_t.

Possible duplicate of [Understanding slice notation](https://stackoverflow.com/questions/509211/understanding-slice-notation) — Paritosh Singh, Feb 27 '19 at 18:52
it contains your answer, if you just read and understand what's already answered there. — Paritosh Singh, Feb 27 '19 at 19:05
Another dupe Q. https://stackoverflow.com/questions/12433695/extract-elements-of-list-at-odd-positions — Paritosh Singh, Feb 27 '19 at 19:08

score 0 · Answer 1 · answered Mar 28 '19 at 20:49

If your list has the same items repeated at the same time step, then:

list1 = ['1t', '1r', '2t', '2r', '3t', '3r']

# list[start:stop:step]
l2 = list1[0::2]
print(l2)

will solve your problem.

However, if what you mean is that you have a list of strings and you need to extract the strings with t on it, then you can just test if t is in the element, like so:

l2 = list()
for i in list1:
    if 't' in i :
        l2.append(i)

print(l2)

How to make a list of certain items from a different list

1 Answers1