ditty | ! ! ! | Incremental Backup library

I have some troubles. Here is my code:

I am struggling as I learn Kivy, but I am making progress. I have an issue right now where I am getting the below error trace.

I feel like i have specified the area which I want to create the scrollview, but it won't allow it and complains that "NoneType" has no 'addWidget' attribute.

What I think I am doing is creating two layout sections within the "Menu" class rule. In that area, I have two "scrollview" widgets that I am building (one to hold the people "drafting" and the other to hold the "available players"). I am building out these scrollview buttons in the python script, but struggling to get them to take appropriately.

Thoughts?

Sorry to ask such a simple question but I didn't see any possible answer in internet.

I just wondering in Sinatra, can I write something like:

I'm trying to understand Public Key encryption so I wrote this little module using PyCryptodome and the RSA/PKCS1_OAEP module on Python 3 to help me along. However, I keep getting an error:

NameError: name 'aesenc' is not defined

This is a two part question:

1. In standalone code (outside a class) the arg = default_val code will work, but I'm pretty sure this code will throw an error (assuming I fix question #2). I also know I can't use self.default_val as that needs an object to be created first. How do I assign a default value (in this case, the private/public key of the object?)

2. With regard to the error message, a vgrep reveals that the suite has been declared before its been called but I still get the NameError. Can someone please take a look and let me know what I'm doing wrong?

Modules: (Breaking into parts as SO keeps jumbling the code)