I fully agree with all the other answers - because of what a great accomplishment writing a book is, you should definitely put it in your CV. The only thing I'd add is, are you looking for a Python job, or would you be willing to do a Python job? Judging from your question, it feels as though you don't, which is why I bring this up.
If I'm correct, and you don't want to work with Python again, I'd try to find a low key way to make that clear from the get-go. Perhaps in your cover letter, or "About Me" section of your resume include a list of technologies that you'd really like to work with, and another list of technologies that you're not specifically looking to work with, but you're willing to under the right conditions. That way you're not explicitly saying that you're unwilling to work in Python - doing that would probably be more of a negative than a positive.
The important part with doing this is it shouldn't be explicit, which is why you want to casually slip it in in your cover letter or About Me section. If you don't have either of those in your resume, and you're working through a recruiter, you should be able to tell the recruiter to not send you any Python opportunities, which should make this part even easier. And you don't want to have one paragraph of your resume saying that you wrote books about Python, and another paragraph saying you're completely unwilling to work with said technology ever again.