[django]How to get topics user replied?

class Topic(models.Model):
    title = models.CharField(max_length=100)
    body  = models.TextField(_('body'), max_length=TEXT_MAX_LENGTH)
    user  = models.ForeignKey(User, related_name='topic_user', editable=False)
    ...

I use 'django.contrib.comments' to reply开发者_运维问答 a topic. How to get topics I replied(just know my user id)?

Thanks.

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It works:

Topic.objects.filter(pk__in=[comment.content_object.pk for comment in Comment.objects.filter(user__exact = request.user)])