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

nl = [['Vienna','2012', 890,503,70],['London','2014', 5400, 879,78],
      ['London','2014',4800,70,90],['Bern','2013',300,450,678],
      ['Vienna','2013', 700,850,90], ['Bern','2013',500,700,90]]
d = {}
for l in nl:
    key = l[0] , l[1]
    value = l[2:]
    if key not in d:
        d[key] = value
    else:
        d[key] = [sum(i)for i in zip(d[key], value)]
print(d)

out:

{('Vienna', '2012'): [890, 503, 70], ('London', '2014'): [10200, 949, 168], ('Bern', '2013'): [800, 1150, 768], ('Vienna', '2013'): [700, 850, 90]}