Ndtyjky

I am looking for a more Pythonic one-liner to split and flatten lists. The original list looks like this:

negative_list = [['apple strudel', 'apple, orange, pear ice cream']]

With the above un-processed list, I need to transform it to the following processed list:

negative_list = ['apple strudel', 'apple', 'orange', 'pear ice cream']

You will notice that 'apple', 'orange', 'pear ice cream' have been split into individual items in the transformed list.

I wrote the following:

negative_list = 

negatives = 

negative_list = [['apple strudel', 'apple, orange, pear ice cream']]

negative_list = [item for sublist in negative_list for item in sublist]

for i in negative_list: 

    if ',' not in i: negatives.append(i.strip())

    else:

        for element in i.split(','): negatives.append(element.strip())

print(negative_list)

print(negatives)

I tried writing a Pythonic one-liner without declaring so many variables, but with little success. Could someone help?

You can try this solution, although this is not recommended for production code:

negative_list = [['apple strudel', 'apple, orange, pear ice cream']]



negative_list = sum([elem.split(", ") for elem in negative_list[0]],)

print(negative_list)

Output:

['apple strudel', 'apple', 'orange', 'pear ice cream']

Another way is to use a nested for loop with list-comprehension:

negative_list = [elem.strip() for item in negative_list[0] for elem in item.split(", ")]

Use itertools.chain.from_iterable with a generator expression:

from itertools import chain



negative_list = [['apple strudel', 'apple, orange, pear ice cream']]



print(list(chain.from_iterable(x.split(', ') for x in negative_list[0])))

# ['apple strudel', 'apple', 'orange', 'pear ice cream']

I think this one resolves the problem

x = [['apple strudel', 'apple, orange, pear ice cream'], ["test", "test1, test2, test3"]]



def flatten(x):

    return sum([(x.split(", ")) for x in sum(x, )], )



print(flatten(x))