Python GUIs for Humans! PySimpleGUI is the top-rated Python application development environment. Launched in 2018 and actively developed, maintained, and supported in 2024. Transforms tkinter, Qt, ...

It does not support a thread-safe increment. It happens to be correct. The reason is 3.10 changed where GIL could be acquired. People should not rely on this "feature" and it could be changed anytime ...