Where can I find API documentation for tkinter?

I am looking for a complete online reference for Python's tkinter module. I've tried to find one by myself, but for some reason I can't.

To clarify, I am not looking for a tutorial. Instead, I would like to have a reference for all the available classes and attributes.

For example, if I write this code:

from tkinter import *
root = Tk()
root.title("My title")

I wonder: what optional arguments does the Tk class accept for instantiation? What are properties and methods for a Tk object? What arguments does title accept? And so on...

"Look at the source" is not an answer to this question, obviously.