return list dictionary of the two biggest numbers in a list of dictionaries

def return_biggest(list_of_dictionaries):
    biggest_key_1 = 0
    biggest_value_1 = 0
    biggest_key_2 = 0
    biggest_value_2 = 0
    for row in list_of_dictionaries:
        key = row.keys()[0]
        value = row.values()[0]
        if value > biggest_value_1:
            biggest_value_2 = biggest_value_1
            biggest_key_2 = biggest_key_1
            biggest_value_1 = value
            biggest_key_1 = key
        elif value > biggest_value_2:
            biggest_value_2 = value
            biggest_key_2 = key
        return {biggest_key_1: biggest_value_1, biggest_key_2: biggest_value_2}