text = 'ROMAlaPARIGIvendita'
from itertools import groupby
from string import ascii_lowercase
# Вариант #1
[''.join(group) for _, group in groupby(text, key=set(ascii_lowercase).issuperset)]
# Вариант #2
[''.join(group) for _, group in groupby(text, key=lambda c: c > 'Z')]