99. References

I used a number of resources to learn Python. Some have far more elaborate texts on the subject. there are ofcourse other sources of information, but this is what I used. I have not listsed all the google searches that helped me with specific questions.
http://effbot.org/tkinterbook/

An introducyion to Tkinter
https://www.programiz.com/article/python-self-why

the explanation of self in python classes
http://spyhce.com/blog/understanding-new-and-init

for the difference between __new__ and __init__.
http://www.mysqltutorial.org/python-mysql/

for the mysql interface.
http://pep8online.com/

for checking PEP8 compliancy.