Thanks for the hint.
I did modify the test_file so it doesn’t import the module anymore (instead I load it from sys.modules).
import sys
this_module = sys.modules[__name__.split('.')[0]]
print( 'TESTPROP: {}'.format(hasattr(this_module, 'TESTPROP')))
setattr(this_module, 'TESTPROP', 'TEST')
print( 'TESTPROP: {}'.format(hasattr(this_module, 'TESTPROP')))
Unfortunately this does not change the output so something es seems to be off:
Loading testModule
TESTPROP: 0
TESTPROP: 1
Loaded testModule
Loading testModule
TESTPROP: 0
TESTPROP: 1
Loaded testModule
Enjoy your holiday!
Edit:
I did some more testing and found that the import issue is related to jython 2.7.1.
Using jython 2.7.0 it works as intended.