Unittest fails to import module

[Martin Schöön]

I know the answer to this must be trivial but I am stuck...

I am starting on a not too complex Python project. Right now the
project file structure contains three subdirectories and two
files with Python code:

code
   blablabla.py
test
   blablabla_test.py
doc
   (empty for now)

blablabla_test.py contains "import unittest" and "import blablabla"

$PYTHONPATH points at both the code and the test directories.

When I run blablabla_test.py it fails to import blablabla.py

I have messed around for oven an hour and get nowhere. I have
done unittesting like this with success in the past and I have
revisited one of those projects and it still works there.

The older project has a slightly flatter structure as it lacks
a separate code subdirectory:

something.py
test
   something_test.py

I have temporarily tried this on the new project but to no avail.

Any leads?

TIA

/Martin