listtree.py

class ListTree:
    '''
    Mix-in that returns an __str__ trace of the entire
    class tree and all its objects' attrs at and above
    self; run by print(), str() returns constructed
    string; uses __x attr names to avoid impacting clients
    recurses to superclasses explicitly, uses str.format
    '''

    def __attrnames(self, obj, indent):
        spaces = ' ' * (indent + 1)
        result = ''
        for attr in sorted(obj.__dict__):
            if (attr.startswith('__') and
                attr.endswith('__')):
                result += spaces + '{}\n'.format(attr)
            else:
                result += (spaces +
                           '{0}={1}\n'.format(attr,
                                     getattr(obj,attr)))

        return result

    def __listclass(self, aClass, indent):
        dots = '.' * indent
        if aClass in self.__visited:
            return '\n{0}<Class {1}:, address {2}:(see above)>\n'.format(dots,aClass.__name__, id(aClass))
        else:
            self.__visited[aClass] = True
            here = self.__attrnames(aClass, indent)
            above = ''
            for super in aClass.__bases__:
                above += self.__listclass(super,
                                          indent+4)
            return '\n{0}<Class {1}, address {2}:\n{3}{4}{5}>\n'.format(dots, aClass.__name__, id(aClass),here,
                                                                        above, dots)

    def __str__(self):
        self.__visited = {}
        here = self.__attrnames(self, 0)
        above = self.__listclass(self.__class__, 4)
        return '<Instance of {0}, address {1}:\n{2}{3}>'.format(self.__class__.__name__, id(self), here, above)


if __name__ == '__main__':
    pass