city1 = 'foo'
city2 = 'bar'

lines = [
    ['fasf', 2],
    ['foo', 1],
    ['saf', 3],
    ['asf', 5],
    ['bar', 15],
    ['fgyj', 6],
    ['bar', 12]
]

city1 = sorted([line for line in lines if line[0] == city1], key=lambda x: x[1])
city2 = sorted([line for line in lines if line[0] == city2], key=lambda x: x[1])


city1 = city1[-1] if city1 else None
city2 = city2[-1] if city2 else None

print(city1)
print(city2)