CHAPTER 47: Read request and response bodies

Boards: 47a and 47b.
Read the surrounding chapter before this lab. All examples are original and synthetic.

PREDICT
The lab uses JSON and the real local baseline to reproduce the bodies on board 47a. It does not start FastAPI, simulate HTTP status codes or claim to test the network. Predict the changed negation result before running.

RUN
From the companion root, run:
python visual_labs/ch47/walkthrough.py
Use python3 if that is your configured command.

COMPARE
Compare the printed values and explanations with both boards. Read expected_output.txt after making your prediction. An assert checks a known expected result and stops if it differs. Temporary output folders are removed after the demonstrations; original course files are not edited.

CHANGE ONE THING
For the real service, follow Chapter 47 to install the declared service dependencies, start Uvicorn locally and open /docs. Submit valid text, empty text and the negation example. Expect success, input validation rejection, and successful transport with wrong meaning respectively. Do not interpret a local body-only lab as proof these HTTP checks ran.

EXPLAIN
State which input changed, which instruction handled that change, and why the resulting output is appropriate. If your prediction differs, identify the first step at which it diverges. Return to the surrounding lesson before adding more complexity.
