title: How do I add a default value to a nested serializer?
body: <p>I am trying to have my &quot;address&quot; API return the default value (empty string &quot;&quot;), but when I use default=&quot;&quot; in the serializer field it returns null instead.
  This is my main serializer (LocationSerializer)</p>
  <pre><code>
  class LocationSerializer(serializers.ModelSerializer):
      id = serializers.UUIDField(read_only=True)
      business_id = serializers.PKRelatedField(Business.any.all(), &quot;business&quot;)
      city_id = serializers.UUIDField(required=True)
      name = serializers.CharField(max_length=48, required=True)
      tax_number = serializers.CharField(max_length=48)
      phone = serializers.PhoneNumberField()
      address = serializers.CharField()
      address_details = AddressEmbeddedSerializer(default=&quot;&quot;, source=&quot;addresses&quot;)
      footer = serializers.CharField()
      is_active = serializers.BooleanField(required=True)
      has_kds = serializers.BooleanField(read_only=True)
      position = serializers.PointField()
      image = serializers.ImageField()
      # profile = LocationProfileSerializer()
      permissions = PermissionSerializer(many=True, read_only=True)
      payment_methods = PaymentMethodEmbeddedSerializer(many=True, read_only=True)
  
      class Meta:
          model = Location
          fields = (
              &quot;id&quot;, &quot;business_id&quot;, &quot;city_id&quot;, &quot;name&quot;, &quot;tax_number&quot;, &quot;phone&quot;, &quot;address&quot;, &quot;address_details&quot;, &quot;footer&quot;,
              &quot;is_active&quot;, &quot;has_kds&quot;, &quot;position&quot;, &quot;image&quot;, &quot;permissions&quot;, &quot;payment_methods&quot;
          )
  </code></pre>
  <p>and this is my nested serializer (AddressEmbeddedSerializer)</p>
  <pre><code>
  
  class AddressEmbeddedSerializer(serializers.ModelSerializer):
      city = serializers.CharField(default=&quot;&quot;)
      area = serializers.CharField(default=&quot;&quot;)
      block = serializers.CharField(default=&quot;&quot;)
      avenue = serializers.CharField(default=&quot;&quot;)
      long = serializers.CharField(default=&quot;&quot;)
      lat = serializers.CharField(default=&quot;&quot;)
  
      class Meta:
          model = LocationAddress
          fields = (
              &quot;city&quot;, &quot;area&quot;, &quot;block&quot;, &quot;avenue&quot;, &quot;long&quot;, &quot;lat&quot;
          )
  </code></pre>
  <p>The value that I am expecting is:</p>
  <pre><code>&quot;address_details&quot;: {
              &quot;city&quot;: &quot;&quot;,
              &quot;area&quot;: &quot;&quot;,
              &quot;block&quot;: &quot;&quot;,
              &quot;avenue&quot;: &quot;&quot;,
              &quot;long&quot;: &quot;&quot;,
              &quot;lat&quot;: &quot;&quot;
          }
  </code></pre>
  <p>Instead what I am getting is:</p>
  <pre><code>&quot;address_details&quot;: null
  </code></pre>
  <p>Please note that all CRUD operations are working, this is only a default value issue</p>