Fixed: I typed all the below and then figured it out. I'm leaving this for future idiots like me.
I had been using the TestFlight version and that must have expired. TestFlight's user experience when test versions expire is horrid. It simply crashes silently. This happens just rarely enough that I forget to check. I reinstalled from the app store and all is well, including the couple files I had stored locally.
I cannot start Pythonista (v 3.3 - latest, iPhone XS, iOS 13.5.1). I briefly see the Pythonista logo/splash screen and then I return to my iphone home screen.
I've tried solutions I've found here and elsewhere, including:
- going to pythonista:// and pythonista3:// from Safari
- going to the Files app and opening one of the python files in my Pythonista iCloud drive folder
- settings "Launch in Safe Mode" in Pythonista settings
- restarting the phone
I've not yet tried uninstalling and reinstalling because I have at least one other file stored locally (i.e. not in iCloud drive, stored locally because of a problem with running extensions from iCloud Drive).
Any other ideas?