Why isn't this infinite recursion?

I would like to ask you about a code in P开发者_开发问答ython:

class UserDict:
    def __init__(self, dict=None, **kwargs):
        self.data = {}
        if dict is not None:
            self.update(dict)
        if len(kwargs):
            self.update(kwargs)
    def clear(self): self.data.clear()

Here, clear(self) is a method of UserDict class, and operates on class's data attribute, right? Won't this function operate on data forever? Because it calls itself every time?

---

UserDict.clear() calls self.data.clear(). self.data is of type dict, not UserDict, so it calls a different method, not itself. It would be an infinite recursion if UserDict.clear() called self.clear() instead of self.data.clear().

---

No, This method calls the clear method of the data dict, which is totally unrelated to UserDict.