Sum nested lists based on condition in Python

Question

I have a nested list looking like this:

[[\'Vienna\',\'2012\', 890,503,70],[\'London\',\'2014\', 5400, 879,78],
 [\'London\',\'2014\',4800,70,90],[\'Bern\',\'201         


        

Answer 1

You should maintain a dictionary as you have outlined in the question. Something like this will help,

cities = {}
for a in list:
    city_key = a[:1]
    if city_key in cities:
        cities[city_key] = [a + b for a, b in zip(a[2:], cities[city_key])]
    else:
        cities[city_tuple] = a[2:]