I have a list like the following:
my_list = ['google', 'microsoft,facebook']
and I need to convert this into:
my_list = ['google', 'microsoft', 'facebook']
I tried doing it this way:
new_list = [item.split(',') for item in my_list]
flat_list = [item for sublist in new_list for item in sublist]
but this method involves unnecessary additional variables and multiple for loops. Is there a way we can make this easier?
The below is simple enough (make en empty list and extend it)
my_list = ['google','microsoft,facebook']
new_list = []
for x in my_list:
new_list.extend(x.split(','))
print(new_list)
output
['google', 'microsoft', 'facebook']
You can do this by converting to the list to string and back to list as follows:
my_list = ['google','microsoft,facebook']
newList = ','.join(my_list).split(',')
Output:
['google', 'microsoft', 'facebook']
You can do this in one nested comprehension:
new_list = [x for item in my_list for x in item.split(',')]
Or use itertools.chain:
from itertools import chain
new_list = [*chain(*(item.split(',') for item in my_list))]
# or the more traditional
new_list = list(chain.from_iterable(item.split(',') for item in my_list))
And if you want to go all out with the functional utils:
from functools import partial
new_list = [*chain(*map(partial(str.split, sep=","), my_list))]
If you insist on doing it in-place, then you can do
for i,e in enumerate(my_list):
my_list[i:i+1] = e.split(",")
You can flat the list with sum(mylist, [])
l = ['google','microsoft,facebook']
ll = sum([s.split(',') for s in l], [])
print(ll)
Output
['google', 'microsoft', 'facebook']
sum to flatten a list. It has quadratic complexity as it builds ever growing new intermediate list objects.
sum for sequence-like objects (str, list, tuple, ...) are always the same.