Getting error ImportMismatchError while running py.test

Question

When I am running tests locally its working fine, but after creating the docker and running inside the container I am getting below error.

    /usr/local/lib/python3.5/site-packages/_pytest/config.py:325: in _getconftestmodules
    return self._path2confmods[path]
E   KeyError: local('/apis/db/tests')

During handling of the above exception, another exception occurred:
/usr/local/lib/python3.5/site-packages/_pytest/config.py:356: in _importconftest
    return self._conftestpath2mod[conftestpath]
E   KeyError: local('/apis/db/tests/conftest.py')

During handling of the above exception, another exception occurred:
/usr/local/lib/python3.5/site-packages/_pytest/config.py:362: in _importconftest
    mod = conftestpath.pyimport()
/usr/local/lib/python3.5/site-packages/py/_path/local.py:680: in pyimport
    raise self.ImportMismatchError(modname, modfile, self)

_pytest.config.ConftestImportFailure: ImportMismatchError('conftest', '/projects/my_project/db/tests/conftest.py', local('/apis/db/tests/conftest.py'))

/apis - its the WORKDIR in Dockerfile.

Answer 1

I have fixed it by removing all __pycache__ pkg under test/ directory, the issue was when I was creating docker image its picking all my __pycache__ and *.pyc files too, at the time when test are running its using my local machine path instead of the path in docker container.

Conclusion: Clear your *.pyc and __pycache__ files before creating a docker image.

Answer 2

You can use the .dockerignore file to exclude all __pycache__ folders from being sent to the docker image context:

.dockerignore file, excludes __pycache__ folders and *.pyc files from all sub/folders:

**/__pycache__
**/*.pyc

Answer 3

I am using Python 3.6. In my case, I was getting ImportMismatchError in modules with the same name under different packages, e.g., A/B/main.py and C/D/main.py. Python 3 does not require __init__.py file in source folders, but adding __init__.py under A/B and C/D solved the issue.

Answer 4

Delete all the .pyc files. You can do this by find . -name \*.pyc -delete