Codility
Translated a book of Programming for my friends.
The book is called "Codility"
All of sample code is based on Python 3.x
You can get the original book from here: https://app.codility.com/programmers/lessons/1-iterations/
(There are some code problem for you.)
Note: Sample code of original book is based on Python 2.x
If you find some errors, You can make issues for that.