Do you have a good project? Do you want to write?
The acquisition folks at Packt are looking for this:
"... demonstrate 4-5 projects over the course of the chapters in order to demonstrate how to build scalable Python projects from scratch. These projects cover some of the most important concepts in Python and the common problems that a Python programmer faces on a day-to-day basis..."
I'm busy already. And most of my examples are owned by my employer. I'm not sure the exceptions are interesting enough.
You get to work with a really good publication team. I've been thrilled.
See https://www.packtpub.com/books/info/packt/contact-us Drop Shaon Basu's name.