This book focuses on programming, modeling, and simulation in Python, and is directed to a broad group of readers - from beginners who want to learn the basics of programming, to more experienced users who want to use Python for Modeling and Simulation in a wide range of fields.The first part of the book presents the basics of programming with concrete examples: this is what you write, and this is what you get.The second part of the book is devoted to the mathematics, mainly linear algebra, and calculus needed for modeling and simulation. The presentation of the mathematics is closely related to the built-in commands and functions in Python.The third part of the book covers modeling and simulation. Following an overview of the topic, different ways to set up models and run simulations as well as to handle and analyze experimental data are discussed. Again, the presentation is hands on, utilizing the built-in commands and functions in Python.The book includes numerous exercises with complete solutions, making it suitable for self-studies. At the book's website (studentlitteratur.se/45430), data files and materials to run all examples are available, as well as complementary materials and solutions to all exercises in the book in terms of executable py-files. In addition, there are py-files for most examples in the book.