Get data back, not prose

1. 01Write ten short customer emails about parcels: lost, damaged, late

   This is Parcel Desk, the small courier the rest of the course works for. Its customers email in claims for refunds.

   ls samples | wc -l

   You pass when: Ten files. Make two of them awkward: one with no parcel number, one with two amounts.

   Check step 1 samples/

2. 02Define a Claim: parcel id, reason (lost, damaged or late), amount, currency

   uv run --with pydantic python -c "from extract import Claim; print(Claim.model_json_schema()['required'])"

   You pass when: The required fields print. Reason only accepts the three values.

   Check step 2 extract.py

3. 03Ask the model for JSON in that shape and validate it

   uv run --with openai --with pydantic extract.py samples/

   You pass when: Ten lines of valid JSON, one per email. The email with no parcel number has a null id, not an invented one.

   Check step 3 extract.py

4. 04On a validation error, send the error back to the model once, then give up loudly

   uv run --with openai --with pydantic extract.py samples/; echo "exit $?"

   You pass when: Exit 0 when all ten validate. Break one on purpose (ask for a fourth reason value) and the exit code is not 0.

   Check step 4 extract.py

The check runs on the computer, not on your word: a step passes when its command exits with 0 there.