Sinan Okay thinks this is interesting:

Calling through the class directly effectively subverts inheritance and kicks the call higher up the class tree to run a specific version. In our case, we can use this technique to invoke the default giveRaise in Person, even though it’s been redefined at the Manager level. In some sense, we must call through Person this way, because a self.giveRaise() inside Manager’s giveRaise code would loop—since self already is a Manager, self.giveRaise() would resolve again to Manager.giveRaise, and so on and so forth recursively