@JonB : None of the files are in site-package (as fare as I understand : site-package are located in "Python Modules/site-package"
Files are in the "working copy" application area, and integrated in Pythonista using the "External Files" "Open ..." option in the sidebar menu of Pythonista.
Yes I'm including B from A (with import). No I'm not importing A from an interactive command line
I've done another test with files located in iCloud from Pythonista directory
import B.B as Be
aa = 1
bb = Be.fun(aa)
Execute A > 1 is printed to the console
Edit B.py and change to
Go to A and Execute A > 1 is still printed to the console.
Kill and relaunch Pythonista
Go to A and Execute A > 2.0 is printed to the console.