The book is based on “First semester in Numerical Analysis with Julia”, written by Giray Ökten. The contents of the original book are retained, while all the algorithms are implemented in Python (Version 3.8.0). Python is an open-source (under OSI), interpreted, a general-purpose programming language that has a large number of users around the world. Python is ranked third in August 2020 by the TIOBE programming community index, a measure of the popularity of programming languages, and is the top-ranked interpreted language. We hope this book will better serve readers who are interested in the first course in Numerical Analysis but are more familiar with Python for the implementation of the algorithms.