https://www.youtube.com/watch?v=gtejJ3RCddE    (numpy)

http://kerenkalif.com/ProgrammingLectures/Advanced%20C/exams/  (C language practice)

https://www.youtube.com/watch?v=nYDKH9fvlBY   (decorators in python)

Python list methods:
https://www.programiz.com/python-programming/methods/list

Python course

https://www.youtube.com/playlist?list=PLEj7E6n4N83H2TyIk8-8h1H4SH7xPntNZ

tkinter tutorial

https://www.geeksforgeeks.org/python-tkinter-tutorial/