Parsing elements from list of list of strings

Question

list = [[1,'abc'], [2, 'bcd'], [3, 'cde']]

I have a list that looks like above.

I want to parse the list and try to get a list that only contains the second element of all lists.

output = ['abc','bcd','cde']

I think I can do it by going over the whole list and add only the second element to a new list like:

output = []
for i in list:
    output.append(i[1])

something like that, but please tell me if there is a better way.

Using list as a variable name isn't recommended. You could always do [x[1] for x in my_list], or list(map(lambda x: x[1],my_list)) if you are in a Lispy mood. — John Coleman
– John Coleman, Commented Mar 22, 2018 at 19:14

Ajax1234 · Accepted Answer · 2018-03-22 19:11:11Z

7

You can use a list comprehension:

l = [[1,'abc'], [2, 'bcd'], [3, 'cde']]
new_l = [b for _, b in l]

Output:

['abc', 'bcd', 'cde']

answered Mar 22, 2018 at 19:11

Ajax1234

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Comments

Vasilis G. · Accepted Answer · 2018-03-22 19:27:25Z

3

Another way to do it is to use itemgetter from operator module:

from operator import itemgetter

l = [[1,'abc'], [2, 'bcd'], [3, 'cde']]

result = list(map(itemgetter(1), l))

print(result)

Output:

['abc', 'bcd', 'cde']

Another not so elegant way is to use the zip function, take the second element from the newly created list and cast it to list:

result = list(list(zip(*l))[1])

answered Mar 22, 2018 at 19:20

Vasilis G.

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