Debugging and Testing a Python Project Workflow

Within a python project, what is the generally accept workflow for debugging and testing ?

Currently I have a test folder that sits at the same level as the project folder. I want the test files (unit tests and others) to call the latest developed Python code in the project in the same-level folder. However for this I need to do some things such as adding folders to the path and relative imports to get it to work. But this seems to break for other project developers.

The alternative is to install the code locally using pip install. But this is a hassle to do every time I want to test.

Can someone please recommend a workflow that is safe and efficient for testing within a project. If the first of these is preferred, what should I do regarding imports and path to get the test code to call the local project code in a reliable way that will work for everyone ?