my_project ./foo ./__init__.py ./bar.py ./tests ./test_foo.py ./test_bar.py
but i used to get confused on how to organize the import(s) and when to use PYTHONPATH for my tests.
my requirements are:
- i want to be able to run my tests both from my_project folder and from the tests folder
- i don’t want to set the PYTHONPATH manually (and i don’t want to add my development path to PYTHONPATH.
- i want to import the lib modules on the test on the same way i would import after the lib is deployed.
(yes i am lazy)
def dumb_true(): return True
the code for test_bar.py should like something like this:
import unittest from foo import bar class TestBar(unittest.TestCase): def test_bar_true(self): self.assertTrue(bar.dumb_true()) if __name__ == '__main__': unittest.main()
the problem here is that you need to set the PYTHONPATH manually.
the first thing that comes in my mind is to add ‘foo’ folder to PYTHONPATH on the test module
... import sys,os sys.path.insert(0,os.path.abspath(__file__+"/../..")) from foo import bar ...
not bad. but you need to add this to every single test module. and hope that your folder structure wont change.
i guess we need a smarter test runner (like nose).
get your code back to just:
... from foo import bar ...
you can just run “nosetests” from the project folder (‘my_project’ in the example above) and it will just work.
the same doesn’t happen if run “nosetests” from the tests folder.
- from nose homepage:
- When nose imports a module, it adds that module’s directory to sys.path; when the module is inside of a package, like package.module, it will be loaded as package.module and the directory of package will be added to sys.path.
so the trick here is to make the tests folder a package (adding __init__.py to it). so in the tests folder you will find:
./tests ./__init__.py ./test_foo.py ./test_bar.py
now from the tests folder you can:
- execute all tests doing “nosetests”
- execute just one file “nosetests test_bar.py”
- check nose docs for more options
and you don’t have to worry about PYTHONPATH at all :)