title: modify django model field on serializer
body: <p>i have a model definition</p>
  <pre><code>Class Book():
            name = textfield()
            edition = textfield() 
  
  </code></pre>
  <p>i want the the name of the book as &quot;edition name&quot; if there is a edition data on the book object. otherwise i want to return only the book. how can i acheive that? can i use a serializermethod on the book serializer as</p>
  <pre><code>class BookSerializer(
  
  ):
      name = serializers.SerializerMethodField()
      def get_name(self,book):
          if book.edition:
              return f&quot;{book.edition}{book.name}&quot;
          return book.name 
  </code></pre>
  <p>this way the name is being saved with the edition number. i dont want to save the edition number with the name. i just want the serializer should return name field as &quot;edition name&quot; if there is a edition else only the name but not save it on the model.</p>