Students can study the programming language Python in several different ways:
Michael Dawson’s book Python Programming for the Absolute Beginner, 3rd edition (Course Technology, 2010) is a self-teaching guide for high school students and (possibly) highly motivated upper middle schoolers. An online companion can be purchased and downloaded at Delmar Cengage Learning.
Hello, World!: Computer Programming for Kids and Other Beginners, 2nd edition (Manning Publications, 2013), is a Python manual intended for middle grades and up, written by engineer Warren Sande and his high school son Carter Sande.
Code Academy offers free introductory sessions in Python (among other languages): https://www.codecademy.com/
The Art of Problem Solving online school offers a live course in beginning and intermediate Python programming: https://www.artofproblemsolving.com/school/course/python1.
A useful index to online Python teaching sites, games, and many other resources, some of them designed especially for K-12 students, can be found at https://wiki.python.org/moin/BeginnersGuide/NonProgrammers.