Code from MOOCs problem sets
Urls of the courses:
Introduction to computational thinking and data science - MIT: https://courses.edx.org/courses/course-v1:MITx+6.00.2x_7+1T2017/
Introduction to computer science and programming using python - MIT: https://www.edx.org/course/introduction-computer-science-mitx-6-00-1x-10
Algorithms on graphs: https://www.coursera.org/learn/algorithms-on-graphs/