'od.__repr__() <==> repr(od)'

def __repr__(self, _repr_running={}):

    call_key = (id(self), _get_ident())
    if (call_key in _repr_running):
        return u'...'
    _repr_running[call_key] = 1
    try:
        if (not self):
            return (u'%s()' % (self.__class__.__name__,))
        return (u'%s(%r)' % (self.__class__.__name__, self.items()))
    finally:
        del _repr_running[call_key]
