Python import src modules when running tests

Question

My source files are located under src and my test files are located under tests. When I want to run a test file, say python myTest.py, I get an import error: "No module named ASourceModule.py".

How do I import all the modules from source needed to run my tests?

Answer 1

You need to add that directory to the path:

import sys
sys.path.append('../src')

Maybe put this into a module if you are using it a lot.

Answer 2

If you don't want to add the source path to each test file or change your PYTHONPATH , you can use nose to run the tests.

Suppose your directory structure is like this:

project
    package
        __init__.py
        module.py
    tests
        __init__.py
        test_module.py

You should import the module normally in the test_module.py (eg from package import module ). Then run the tests by running nosetests in the project folder. You can also run specific tests by doing nosetests tests/test_module.py .

The __init__.py in the tests directory is necessary if you want to run the tests from inside it.

You can install nose easily with easy_install or pip :

easy_install nose

or

pip install nose

nose extends unittest in a lot more ways, to learn more about it you can check their website: https://nose.readthedocs.org/en/latest/

Answer 3

On my system (Windows 10), I was required to do something like this:

import sys
import os
sys.path.append(os.path.dirname(os.path.realpath(__file__)) + "/../src")

Appending the relative directory directly to sys.path did not work

Answer 4

The best (most manageable) solution appears to be using a virtualenv and setuptools/distribute to install a development copy of your (src) package. That way your tests execute against a fully "installed" system.

In the pystest docs there is a section on "good practices" explaining this approach, see here .

Answer 5

For those using Pytest:

• Make sure src is recognized as a package by putting an empty __init__.py inside.
• Put an empty conftest.py in the project folder.
• Make sure there is no __init__.py in the test directory.

Looks like this:

project
    conftest.py
    src
        __init__.py
        module.py
    test
        test_module.py

And make sure module.py contains the line:

from src import module

Source: Pytest docs