With the latest Pythonista Beta v. 3.3 (330025), installed today, i.e. 20 Feb., 2020, I get the same crash in my App I got with the last Beta.
I tracked it down to the very first line of code that executes in my App! I commented out that line, and my App runs successfully.
That line is:
A great many lines of code are omitted both before and after the code snippet shown.
# Prevent iPhone from going to sleep while this program runs. console.set_idle_timer_disabled(True) # Create an instance of a class that derives from ui.View. # <code-omitted>
If I comment out that one line of code, the program does not crash.
I am running that on an iPhone 6s running IOS 13.3.1
I'm having exactly same issue since updating to 3.3 earlier today. Commenting out the "console.set_idle_timer_disabled(True)" helps. iPhone 8 and 13.3.1. Phone reboot not help.