Remove hard dependency on psycopg2

[intgr]

One would reasonably expect django-celery-results to work with other databases without installing psycopg2.

The hard dependency was added in PR #290, probably unintentional without fully understanding this aspect.

[intgr]

As a work-around, I have added psycopg2-binary dependency to my project, so it's not a big deal.

[auvipy]

As a work-around, I have added psycopg2-binary dependency to my project, so it's not a big deal.

can we add that to this package as well in this PR?

[abdelwahebmoalla]

when is this going to be merged and relased ?

[intgr]

can we add that to this package as well in this PR?

This PR intends to make the dependency optional.

IMO seems a bit odd if a database-agnostic Django app has a dependency on one particular database driver.

If there's a need to add MariaDB or Oracle driver-specific logic, will this project also add a dependency for their respective drivers?

[auvipy]

then the dependency should be removed from requirement as well?

[intgr]

Maybe my PR title was a little misleading. psycopg2 is not currently a declared dependency of the package. So django-celery-results fails with an ImportError, it does not install the psycopg2 package. There's nothing to remove.

(The dependency is only in requirements/test.txt, that one should be kept I assume)

[auvipy]

what confuses me is the test failures with https://github.com/celery/django-celery-results/pull/294/files

[saemideluxe]

Thanks for fixing this. I just encountered the issue after an upgrade. Any chance that there will soon be a new pip release including the fix?