def edit_handler(self, obj, attr):
        "Activate the line editor"
        def load(caller):
            "Called for the editor to load the buffer"
            old_value = obj.attributes.get(attr)
            if old_value is None and not isinstance(old_value, basestring):
                typ = type(old_value).__name__
                self.caller.msg("{RWARNING! Saving this buffer will overwrite the "\
                                "current attribute (of type %s) with a string!{n" % typ)
                return str(old_value)
            return old_value
        def save(caller, buf):
            "Called when editor saves its buffer."
            obj.attributes.add(attr, buf)
            caller.msg("Saved Attribute %s." % attr)
        # start the editor
        EvEditor(self.caller, load, save, key="%s/%s" % (obj, attr))
dataset/ETHPy150Open evennia/evennia/evennia/commands/default/building.py/CmdSetAttribute.edit_handler/operator `is not` -> `is`