title: age filter in django
body: <p>I have products in my ecommerce. How can I group them in age groups like child, adult, senior? But one product can be on morethan one group. Example a cloth can be for both adult and senior. What method should I choose?</p>
  <pre><code>class Product(models.Model):
      user = models.ForeignKey(User, on_delete=models.CASCADE)
      category = models.ForeignKey(Category, on_delete=models.CASCADE)  # many to one relation with Category
      title = models.CharField(max_length=150)
      keywords = models.CharField(max_length=255)
      description = models.TextField(max_length=255)
      brand = models.TextField(max_length=50, blank=True, null=True)
      image = models.ImageField(null=False, upload_to='images/')
      price = models.DecimalField(max_digits=12, decimal_places=2, default=0)
      detail = RichTextUploadingField()
      slug = models.SlugField(null=False)
  
      def __str__(self):
          return self.title
  </code></pre>