This is the starter project for the exercises in the "First Steps in Domain-Driven Design" course for O'Reilly. If you are more of a Java person, take a look at the Java version of this codebase. If you prefer dotnet, take a look at the C# version (Thanks to @BAPostma for contributing this).

You should be able to fork and then clone this repo to get an almost-empty python project ready to work with.

• python 3.7+
• pytest 6.2.4+ (pip install -r requirements.txt)
• IDE of your choice
• Git client (unless you already have one in your IDE)

A directory first-steps-in-ddd-python containing this README.md, a solution file with the code and test projects. Source files in src and the unit tests that live in tests directory containing some example unit tests (test_a_police_investigation.py, test_a_precharge_decision.py and test_a_criminal_case.py) and associated starter classes found in src/justice_app.py (e.g. PoliceInvestigation, PNCId, Suspect.py) and an Enum, CriminalOffence.

The training relies entirely on your writing unit tests (ideally you use test-driven development), so you want to be able to run them very quickly.

Open the newly checked out project in your IDE (point it at the top-level project directory). Install the requirements from requirements.txt Then check you can execute all the tests with the click of a single mouse button, or ideally a single keyboard shortcut. Make sure you are running the tests with pytest instead of the default unittest

Additionally, you can run the tests from the command line. Open a terminal and change to the top-level project directory. Then run the command pytest.

You ought to see your tests running, and all but one of the tests run successfully.

The failing test is where we will start exercise one.

We're going to work on this code based on a Domain Expert Statement from a Public Prosecutor. If you want to read it in advance, that'll help you in the first workshop exercise and beyond.