title: python define a group of classes
body: <p>Like:</p>
  
  <pre><code>class base:
      pass
  classes = ["class1", "class2", "class3", "class4"]
  for classname in classes:
      class classname(base):
          pass 
  </code></pre>
  
  <p>I search for dynamic class define, and it's too complicate.</p>
  
  <p>I need an easy solution.</p>