title: print nested objects with python and __repr__
body: <p>I'm curious how I should be be implementing the <strong>repr</strong> method of an object that contains other objects that implement <strong>repr</strong>.</p>
  
  <p>For example (pythonish):</p>
  
  <pre><code>class Book():
      def__repr__
          return 'author ... isbn'
  
  class Library(): 
      def __repr__:
          me ='['
          for b in books:
              me = me + b.repr()
          me = me + ']'
          return me
  </code></pre>
  
  <p>Do I have to directly call that repr() method? i can't seem to just concat it and have it implicitly convert it to a string.</p>