# area in square km:
area = [1572, 891.85, 605.77, 1285,
105.4, 414.6, 228, 755,
525.2, 517, 101.9, 310.4,
181.8]
city_frame["area"] = area
print(city_frame)
country area population
London England 1572.00 8615246
Berlin Germany 891.85 3562166
Madrid Spain 605.77 3165235
Rome Italy 1285.00 2874038
Paris France 105.40 2273305
Vienna Austria 414.60 1805681
Bucharest Romania 228.00 1803425
Hamburg Germany 755.00 1760433
Budapest Hungary 525.20 1754000
Warsaw Poland 517.00 1740119
Barcelona Spain 101.90 1602386
Munich Germany 310.40 1493900
Milan Italy 181.80 1350680