The 4th _<I>Learning Python_</I>, for Python 3.X bifurcation.

This, and the 4th _<I>Pocket Reference_</I>, 
were put out to cover the new and backward-incompatible Python 3.X,
released the prior year.  Much of this edition's 
_<A HREF="https://learning-python.com/about-lp.html">growth_</A>
owes to having to cover two different language lines; the vast 
majority of readers would still be using 2.X for many years to come.

Python 3.X broke most Python programs at the time, and many people saw 
it as biased and rude, which is one reason its adoption was very slow.
2.X was not retired until 2020, some 12 years later, when it still 
had a large and loyal userbase.

That said, 3.X is fully usable today, its Unicode model is more
coherent, and it's still a lot nicer than Java, C++, Perl, and 
their ilk—especially if you ignore its bleeding-edge new stuff
(and perennial douche moves).