title: Update value of the object which is inherited by str class
body: <p>I have a class which inherits from <code>str</code>:</p>
  <pre><code>class Gender(str):
      def __init__(self, *args, **kwargs):
          super().__init__()
          self.VALIDATION_META = {&quot;valid&quot;: None, &quot;errors&quot;: list()}
          self.gender = str()
  </code></pre>
  <p>Now I create an object with some value.
  <code>obj = Gender('Male')</code>
  How I can replace the value only within the object.</p>
  <p>e.g obj = 'Female' object type should be the Gender</p>