In the yield statement documentation
(http://docs.python.org/3.0/reference/simple_stmts.html#the-yield-statement),
the old way of calling generators is used:

"The body of the generator function is executed by calling the
generator’s next() method repeatedly until it raises an exception."

This should be changed to something like:

"The body of the generator function is executed by calling the next()
function on the generator repeatedly until it raises an exception."

Or just replace next() with __next__(), and fix the next paragraph as well.