[Tutor] __abs__() not acting as expected

[Jim Byrnes]

I am reading Practical Programming - An Introduction to Computer Science 
Using Python 3.  They give this example:

 >>> abs(-3)
3

 >>> -3 .__abs__()
3

When I try it in idle or a terminal I get different results.

Python 3.3.5 (default, Mar 12 2014, 02:09:17)
[GCC 4.6.3] on linux

 >>> abs(-3)
3

 >>> -3 .__abs__()
-3

If I use a variable it works.

 >>> x = -3
 >>> x.__abs__()
3

I am curious as to what is happening.  Is the book wrong?  I checked 
it's errata and nothing is mentioned.

Regards, Jim