Month, Jan, Feb, March....etc.

def hottest_city(csv_filename):
    import csv
    file = open(csv_filename)
    header = next(file)
    data = csv.reader(file)
    city_maxlist = []
    for line in data:
        maxtemp = 0.0
        for temp in line[1:]:
            if float(temp >= maxtemp:
                maxtemp = float(temp)
        city_maxlist.append([maxtemp, line[0])
    maxtempcity = 0.0
    for city in city_maxlist:
        if city[0] >= maxtempcity:
            maxtempcity = city[0]
    citylist = []
    for line in data:
        for temp in line:
            if temp == maxtempcity:
                citylist.append(line[0])
    return (maxtempcity, citylist)