Google: search for websites containing exactly the given word or pharase

To search for websites containing exactly the given word or phrase, one can use allintext: operator. For example:
allintext:"some phrase"

Python 3 and tkinter: scroll canvas with mouse wheel and drag it around with middle mouse button

This is an example in Python 3.4 running in 64-bit Ubuntu 14.04 of a canvas that can be scrolled with mouse wheel and dragged around with middle mouse button. Hope this example will be useful to you.