VSCode cannot locate packages in unit tests

Question

I've got a project with a suite of Python unit tests (using the unittest framework) that import Pytorch and cv2. I am able to run them all from the command line with

python -m unittest discover -s tests/

But get import errors in the VSCode UI when I try to load them:

Failed to import test module: test_overlays
Traceback (most recent call last):
  File "XXX\AppData\Local\Continuum\anaconda3\lib\unittest\loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "XXX\AppData\Local\Continuum\anaconda3\lib\unittest\loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "XXX\tests\test_overlays.py", line 13, in <module>
...
    import torch
ModuleNotFoundError: No module named 'torch'

My project is structured as a "wrapper application" importing utilities from a core library:

main_proj/
   library/
      packages and modules importing torch
   tests/
      unit tests for the application

The tests generally test only the wrapper application (there are separate tests for the library), but I occasionally import modules from library/.

Because the tests are outside main_proj/library, I need to add the library explicitly to the path at the top of each unit test:

import unittest
import sys
import os, os.path

sys.path.append(os.path.join(os.getcwd(), 'library'))

Why does this arrangement work just fine from the command line, but not from VSCode?

Answer 1

What resolved this issue was to:

1. Update VSCode to the latest version

2. Switch to an older Python 3.6 Anaconda environment (Ctrl+Shift+P, then Choose Interpreter...) -- I'm not sure this step is necessary

3. Close VSCode

4. Delete the Python extensions and reinstall them:

   • From git bash:

     cd ~/.vscode/extensions
     rm -fr *python*
     

   • Re-open VSCode and navigate to the extensions panel (Cog wheel->Extensions) and search for Python)

Afterward, I was able to use my Python 3.8+Torch 1.12 environment without any hitches.

It seems that something between VSCode and the Python extensions can occasionally get corrupted and requires a clean start in order to recover.