Filter many to many field in Django model

Question

I have these 2 models in a Django app:

class Tag(models.Model):
   name =  models.CharField(max_length=100, blank=False, unique=True)

class Article(models.Model):
    title = models.CharField(max_length=100, blank=True, default='')
    tags = models.ManyToManyField(Tag, blank=True)

In my views, I'd like to filter the articles and only get the articles where articles.tags contains the tag with id == 2. How can I do that ?

I tried

tags = Tag.objects.filter(pk=2);

articles = Article.objects.filter(len(tags) > 0) but I have this error 'bool' object is not itterable.

Answer 1

This is the correct way of filtering manytomany in django

articles = Article.objects.filter(tags__in=[2])

or

tags = Tag.objects.filter(pk=2)
articles = Article.objects.filter(tags__in=tags)