title: How to add elements from one class to another class list, python
body: <pre><code>class lista(object):
      listanumere=[]
      def printer(self):
          print self.listanumere
      def adds(self,numar):
          self.listanumere.append(numar)
  
  class movies():
      def __init__(self,ide,nume):
          self.__nume=nume
          self.__ide=ide
  
  listarez=lista
  a=movies(1,"David")
  lista.adds(a)
  lista.printer()
  </code></pre>
  
  <p><strong>Error:</strong></p>
  
  <pre><code>TypeError: unbound method adds() must be called with lista instance as first argument (got movies instance instead)  
  </code></pre>
  
  <p>So my question is: How to make a class which contains a list of elements defined in another class, for example a class which contains the list of movies and some methods which modify the list for example add a new movie or remove a movie with a certain ID?</p>