@receiver(pre_save, sender=Posts)
def my_handler(sender, **kwargs):
instance = kwargs.pop('instance', None)
result_list = []
for w in instance.post.split():
res = ''
for i in w.lower():
if i.isalpha():
res += i
if res and not res in result_list:
result_list.append(res)
for i in result_list:
obj, is_created = DictWords.objects.get_or_create(name=i)
instance.list_words.add(obj)