When collecting data which is received from a string via splitting, we would like to add the new elements to the existing list:

examples/lists/split_extend.py
from __future__ import print_function

lines = [
    'abc def ghi',
    'hello world',
]

collector = []

for l in lines:
   collector.extend(l.split(' '))
   print(collector)

# ['abc', 'def', 'ghi']
# ['abc', 'def', 'ghi', 'hello', 'world']