Python import from parent directory

Question

I have the following:

         ModuleFolder               |               |-->. ModuleFile.py .               |               '-->. TestsFolder .                          |                          '---> UnitTest1.py 

I'm trying to import from the parent directory. In this case I am trying to run "UnitTest1.py" from the test folder, and import from the directory immediately above it (the file "ModuleFile.py").

• I know there are plenty of answers to this already. SO Question1, SO Question2, Every Other SO Question. I just couldn't find "using ../" as a relative import rather than the explicit path.
• I know that as of Python 2.5 they supported "relative imports" as per the documentation that mentions the use of from .. import * but I am specifically trying to do an import MyModuleName so I can be more explicit in the unittest and avoid mangling/collisions of names.

What I am doing (and it is working for me) is the following:

sys.path.append("../") 

And then importing what I need from the parent directory.

• Yes, there is an __init__.py in the parent directory,
• No, my parent path is not part of the Python path or environment variable
• Why don't I just add the parent path to the sys.path? Because it's relative. If I am running from /home/workspace/MyModule/unittests/ and my module is under /home/workspace/MyModule/ I assumed adding /home/workspace/MyModule/ to the path won't necessarily be true if a coworker runs this on his machine under his own directory of /home/documents/MyModule.

My Question:

Is this Python-proper? If not, what's wrong with this. Is there a better way? Or is this truly an RTFM moment where the answer is in one of the 7+ SO questions I've already looked at? (I saw those all recommending the explicit path rather than the relative path approach I took).

Other useful information:

• Python 2.6
• Working in Linux but could just as easily jump over to Win.

Answer 1

Don't run the test from the tests folder. Run it from the root of your project, which is the module folder. You should very rarely need to muck with either sys.path or PYTHONPATH, and when you do, you're either causing bugs for other libraries down the road or making life harder on your users.

python -m TestsFolder.UnitTest1 

If you use a test runner like py.test, you can just run py.test from the root of your checkout and it'll find the tests for you. (Assuming you name your tests something more like test_unit1.py. Your current naming scheme is a little unorthodox. ;))