def get_co_occurrences(data):
    com = defaultdict(dict)
    for temp in data:
        for i in range(len(city_list)-1):
            for j in range(i+1, len(city_list)):
                w1, w2 = city_list[i], city_list[j]
                if " " + w1 + " " in temp and " " + w2 + " " in temp:
                    print(w1,w2)
                    if com[w1].get(w2) is None:
                        com[w1][w2] = 1
                    else:
                        com[w1][w2] += 1
    return com