Add book mention [preface.md]

preface.md

@@ -98,6 +98,7 @@ I could list a few developer-friendly **books for practical cryptography** with
 * [**Cryptography for Developers**](https://books.google.bg/books?id=VaiYIZHduXQC) (by Tom Denis) - provides solid fundamentals in cryptography and crypto algorithms, along with implementations in **C** and **assembler** with lots of code examples. Written in the middle between an academic style and a developer style. Covers hashes, HMAC, AES, slightly RSA and ECC. Slightly outdated (published in 2007).
 * [**Beginning Cryptography with Java**](https://books.google.bg/books?id=WLLAD2FKH3IC) (by David Hook) - a reference for JCA, JCE, JSSE and the Bouncy Castle crypto library with lots of code examples in **Java** (published in 2005, outdated).
 * [**Cryptography for JavaScript Developers: Web Cryptography API, SJCL**](https://books.google.bg/books?id=8oBxDwAAQBAJ) (by Anish Nath) - a reference full of code examples in **JS**, but does not explain the concepts like symmetric ciphers, authenticated encryption, etc. (published in 2018).
+* [**Practical Cryptography in Python**](https://github.com/Apress/practical-cryptography-in-python) (by Seth Nielson and Christopher K. Monson) - a book of 371 pages, published in 2019 with lots of code examples in **Python**.
 * [**Hands-On Cryptography with Python**](https://books.google.bg/books?id=LsNiDwAAQBAJ) (by Samuel Bowne) - nice mini book (87 pages, published in 2018) with lots of code examples in **Python**, but with very limited scope: hashes, AES and RSA. No signatures, no elliptic curves, no MAC and key derivation functions.
 * [**Cryptography in C and C++**](https://books.google.bg/books?id=5cEYAAAAQBAJ) (by Michael Welschenbach) - guidelines how to implement crypto algorithms like AES and RSA in **C** / **C++**. No signatures, no elliptic curves, no MAC and key derivation functions. Published in 2005 (outdated).