Function returns "NoneType"

[micseydel]

The code you post should be runnable. Yours is missing imports, at the very least. Ideally you would just remove code that uses them and distill the problem into the absolute minimum needed to reproduce, which is likely just 5-10 lines. Also, you only posted part of the stack trace, not the whole thing, which we need (though a stack trace is most useful when we have the exact code that reproduced it).