Django: returning count values

Question

With the following code I want to return the count this works...

def contact_count(self):
    return len(self.contacts)

However, if the len is 0 is returns blank and I want it to be 0.

So I have tried

def contact_count(self):
    if len(self.contacts) == 0:
       return 0
    else:
      return len(self.contacts)

Is there a better way I should be handling this?

UPDATE:

So to update my question as asked this is how contacts is defined...

models.py

class Groups(models.Model):
    name = models.CharField(max_length=60)

    def contact_count(self):
        return len(self.contacts)

class Contacts(models.Model):
    first_name = models.CharField(max_length=60)
    last_name = models.CharField(max_length=60)
    #FK
    groups = models.ManyToManyField(Groups, related_name='contacts')

As you can see if comes from the related_name

return 0 if not self.contact else len(self.contacts) although it's only a matter of style really as what you have works — Timmy O'Mahony
– Timmy O'Mahony, Commented Mar 13, 2013 at 21:25
what do you mean len(self.contacts) returns blank? Maybe you get error page because you're trying to len(None) which is exception? — Marius Grigaitis
– Marius Grigaitis, Commented Mar 13, 2013 at 21:25

Facundo Casco · Accepted Answer · 2013-03-13 21:37:35Z

3

You should use self.contacts.count().

See Django docs on many to many relations for more details.

answered Mar 13, 2013 at 21:37

Facundo Casco

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