Python-3.2 coroutine: AttributeError: 'generator' object has no attribute 'next'

Quoting from Python Essential Reference, by David Beazley, page 20:

Normally, functions operate on a single set of input arguments. However, a function can also be written to operate as a task that processes a sequence of inputs sent to it. This type of function is known as a coroutine and is created by using the yield statement as an expression (yield) as shown in this example:

def print_matches(matchtext):
    print "Looking for", matchtext
    while True:
        line = (yield)       # Get a line of text
        if matchtext in line:
            print line

To use this function, you first call it, advance it to the first (yield), and then start sending data to it using send(). For example:

>>> matcher = print_matches("python")
>>> matcher.next() # Advance to the first (yield)
Looking for python
>>> matcher.send("Hello World")
>>> matcher.send("python is cool")
python is cool
>>> matcher.send("yow!")
>>> matcher.close() # Done with the matcher function call

Based on that information, I wrote this code:

#!/usr/bin/python3.2
import sys

def match_text(pattern):
    line = (yield)
    if pattern in line:
        print(line)

x = match_text('apple')
x.next()

for line in input('>>>> '):
    if x.send(line):
        print(line)

x.close()

But I get an error message like:

Traceback (most recent call last):
  File "xxx", line 9, in <module>
    matcher.next() # Advance to the first (yield)
AttributeError: 'generator' object has no attribute 'next'

Why doesn’t this code (or the code from the book, for that matter) work in Python 3.2? It seems that what is supposed to be a coroutine, is treated as a generator instead – why? What is going on here?