class SomeSerializer(serializers.HyperlinkedModelSerializer):

    my_json_url = serializers.SerializerMethodField()

    def get_my_json_url(self, obj):
        return "../../public/images/"

    class Meta(object):
        model = Product
        fields = ('url', 'my_json_url')

class ProductSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Product
        # Product.image=Product.image.replace("http://127.0.0.1:8000/api/tovars/")
        fields = ['name', 'price', 'description','discount_price' ,'image' ]