Which is the preferred test package structure for packages containing subpackages:
Tests in Subpackages?
a/ __init__.py b.py c/ __init__.py cc.py test/ __init__.py test_cc.py d.py test/ __init__.py test_b.py test_d.py
This structure suggests that each subpackage is a cohesive unit that can be tested (and possibly later released) by itself.
Subpackages in Tests?
a/ __init__.py b.py c/ __init__.py cc.py d.py test/ __init__.py test_b.py test_c/ __init__.py test_cc.py test_d.py
This structure does a better job of keeping the tests in one place, but makes it a little harder to run the tests for a particular subpackage.