Picking out items from a python list which have specific indexes

Question

I'm sure there's a nice way to do this in Python, but I'm pretty new to the language, so forgive me if this is an easy one!

I have a list, and I'd like to pick out certain values from that list. The values I want to pick out are the ones whose indexes in the list are specified in another list.

For example:

indexes = [2, 4, 5]
main_list = [0, 1, 9, 3, 2, 6, 1, 9, 8]

the output would be:

[9, 2, 6]

(i.e., the elements with indexes 2, 4 and 5 from main_list).

I have a feeling this should be doable using something like list comprehensions, but I can't figure it out (in particular, I can't figure out how to access the index of an item when using a list comprehension).

Thanks,

Ben

Answer 1

t = []
for i in indexes:
    t.append(main_list[i])
return t

Answer 2

I think Yuval A's solution is a pretty clear and simple. But if you actually want a one line list comprehension:

[e for i, e in enumerate(main_list) if i in indexes]

Answer 3

[main_list[x] for x in indexes]

This will return a list of the objects, using a list comprehension.

Answer 4

map(lambda x:main_list[x],indexes)