def count_words(sentence):
    dict = {}
    separators = [".", ",", ":", "!", "?", "\n", "\t", "'", " ", '"']

    previous_i = 0
    for i, chr  in enumerate(sentence):
        if chr in separators:
            word = sentence[previous_i:i]
            previous_i = i + 1
            word = word.lower().strip(" ")
            if word in separators or word == "":
                continue
            if word in dict:
                dict[word] = dict[word] + 1
            else:
                dict.update({word : 1})
    return dict

print(count_words("""To je heslo: 'HESLO 123'!", zvolala postava zo seriálu Panelák.\nPotom som utiekol."""))