Django Slugify with blank object field printing "none" in url

Question

class Entry(models.Model):
    name = models.CharField(max_length=200, null=True, blank=True)
    city = models.CharField(max_length=200, null=True, blank=True)
    zip_code = models.ManyToManyField('EntryTwo', related_name="entries", blank=True)
    slug = models.SlugField(null=True, unique=True, max_length=300)
    id = models.UUIDField(default=uuid.uuid4, unique=True, primary_key=True, editable=False)
    
    def __str__(self):
        return self.name

    def get_absolute_url(self):
            return reverse("index", kwargs={"slug": self.slug})
    
    def save(self, *args, **kwargs):
    self.slug = slugify(f"{self.name}-{self.city}-{self.zip_code}")
    return super().save(*args, **kwargs)

Url is being returned as www.example.com/name-city-zip_code.

If an object has is missing a city, then url is returning: www.example.com/name-none-zip_code

How can I add an if statement in the F string in order to only display an object field if it is not None?

I tried the following but did not work:

self.slug = slugify(f"{self.name}-{self.city}-{self.zip_code}").replace("none","").

self.slug = slugify(f"{self.name}-{self.city}{% if self.zip_code %}-{self.zip_code}{% endif %}").

self.slug = slugify(f"{self.name}-{self.city}if self.zip_code:-{self.zip_code}").

self.slug = slugify(f"{self.name}-{self.city}if self.zip_code-{self.zip_code}").

Answer 1

you can do something like this and to make sure that the slug is unique i will add the id to the slug.

class Entry(models.Model):

    ...................

    def save(self, *args, **kwargs):
        url_slug = ''
        name = self.name
        if name:
            url_slug += name +' '

        city = self.city
        if city:
            url_slug += city +' '

        id = self.id
        if id:
            url_slug += str(id)

        self.slug = slugify(url_slug.strip())
        return super().save(*args, **kwargs)