test for a tree like structure encoded & decoded by jsonpickle

cyclical_test.py

import jsonpickle

class Node(object):
    def __init__(self, name):
        self._name = name
        self._children = []
        self._parent = None


    def add_child(self, child, index=-1):
        if index == -1:
            index = len(self._children)
        self._children.insert(index, child)
        child._parent = self

class Document(Node):
    def __init__(self, name):
        Node.__init__(self, name)

    def __str__(self):
        ret_str ='Document "%s"\n' %self._name
        for c in self._children:
            ret_str += repr(c)

        return ret_str

    def __repr__(self):
        return self.__str__()

class Section(Node):
    def __init__(self, name):
        Node.__init__(self, name)

    def __str__(self):
        ret_str = 'Section "%s", parent: "%s"\n' % (self._name, self._parent._name)
        for c in self._children:
            ret_str += repr(c)
        return ret_str

    def __repr__(self):
        return self.__str__()


class Question(Node):
    def __init__(self, name):
        Node.__init__(self, name)

    def __str__(self):
        return 'Question "%s", parent: "%s"\n' % (self._name, self._parent._name)

    def __repr__(self):
        return self.__str__()


if __name__ == '__main__':
    # set up the cyclical structure
    document = Document('My Document')
    section1 = Section('Section 1')
    section2 = Section('Section 2')
    question1 = Question('Question 1')
    question2 = Question('Question 2')
    question3 = Question('Question 3')
    question4 = Question('Question 4')
    document.add_child(section1)
    document.add_child(section2)
    section1.add_child(question1)
    section1.add_child(question2)
    section2.add_child(question3)
    section2.add_child(question4)

    print "Original Document Structure: "
    print document

    output_file = open(path, 'w')

    jsonpickle.set_encoder_options('json', indent=2)
    pickled = jsonpickle.encode(document)

    unpickled = jsonpickle.decode(pickled)

    print "Document Structure after jsonpickle.decode()"
    print unpickled