Create sets from list in order

Question

I am trying to create a set from a list which I need it to be in order.

someList = ['from', 'from', 'who', 'are', 'are', 'frost', 'fire', 'are']

someSet = set(list)

Doing that yields a random ordered sets.

I need it to always be in order like

someSet >> {'from', 'who', 'are', 'frost', 'fire', 'are'}

Sets are *unordered*. What exactly are you trying to achieve? — jonrsharpe, Oct 31 '14 at 18:18
I am trying to get the first x element of a list, which can not be a repeat. So order is important here. — Gavin, Oct 31 '14 at 18:21
http://stackoverflow.com/questions/1653970/does-python-have-an-ordered-set — vaultah, Oct 31 '14 at 18:23
Then a `set` (on its own, at least) is not the right data structure for you. — jonrsharpe, Oct 31 '14 at 18:25

score 0 · Answer 1 · answered Oct 31 '14 at 18:21

0

you can do like this

someist = ['from', 'from', 'who', 'are', 'are', 'frost', 'fire', 'are']
new_list[]
for x in somelist:
    if x not in new_list:
        new_list.append(x)

In the above code, if new_list will have the element it will not append, so you will get in order

answered Oct 31 '14 at 18:21

Hackaholic

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Membership testing in a list is `O(n)`; you should still be using a `set` to keep track of the items already seen. – jonrsharpe Oct 31 '14 at 18:21

Create sets from list in order

1 Answers1