Python 模块单元测试

Question

I want to run a Python unittest by invoking the

python -m unittest discover 

command. Two packages are in in a module as follows

test
 |_ mytest.py
my_module
  |__foo.py
  |__bar.py 

where in bar.py

#bar.py
from foo import baz
# Do things using baz

The problem is that when the unittest discover command runs, foo cannot be found in bar.py anymore. This because my_module is seen as a proper module inside the python test, so I would need to do

from my_module.foo import baz

but that wouldn't work when using the module stand-alone. So what to do? I see 2 options, but they are not that neat so I would like more input:

1. Let init .py in my_module add my_module to PYTHONPATH
2. Let mytest.py add my_module to PYTHONPATH

However, I found this page stating that

Never add a package directory, or any directory inside a package, directly to the Python path.

The arguments put forth seems to make sense, and as our repository grows constantly we should try to get this right.

What would you do?

Answer 1

If you ALSO want to have those modules STANDALONE, then they should NOT be INSIDE another module. Because that way, you are ALREADY violating "Never add a page directory inside a module..." And then you could add that path to the pythonpath as well.

Answer 2

If you don't want to make any changes to my_module to turn it into a package that can be imported by your unit tests, one solution is to move your unit tests into my_module . For example, you could have:

# my_module/bar.py

from foo import baz

# my_module/test_bar.py

import bar

# Tests...

Then run python -m unittest discover from inside my_module or python -m unittest discover --start-directory my_module from the project root.

By the way, I think there might be some confusion with terminology here. In Python, a module is typically a single .py file, and a package is typically a folder that contains a group of .py files, one of which is __init__.py . For that reason, foo and bar are probably really modules, and my_module is probably a package (or would be if it had an __init__.py file).