Bridge course (Week 0) — the foundations¶

~8 min read · Examinable: 🔥 (assumed knowledge — basics woven into every scenario) · GA0 · GA1

The bridge course covers fundamentals the exam treats as assumed knowledge: terminal navigation, file operations, virtual environments, HTTP basics, and git fundamentals. You won't see standalone "what is cd" questions, but these skills appear inside every scenario.

Course files: installation · file structure · path reading · terminal navigation · basic scripting · virtual environments · uv workflow · VS Code setup · HTTP fundamentals · API testing with curl · Chrome DevTools · git basics · GitHub SSH login.

pwd              # where am I?
ls -la           # what's here? (all files, details)
cd ~/projects    # go to a directory
mkdir new-dir    # create a directory
touch file.txt   # create an empty file
cp src dst       # copy
mv old new       # move / rename
rm file          # delete

The exam connection: these appear inside scenario questions — "the student navigates to the project directory and runs..." You're expected to read them fluently, not be tested on them directly.

Virtual environments and uv — Python dependency isolation¶

The problem: project A needs pandas 2.0, project B needs pandas 1.5. Installing both globally breaks one of them.

The solution: virtual environments — isolated Python installations per project. uv handles this automatically:

uv init my-project    # create a project
uv add requests       # add a dependency (creates .venv automatically)
uv run script.py      # run in the project's environment

The exam connection: this is the same reproducibility concept as Docker's requirements.txt and pinned dependencies — same code, same environment, everywhere.

HTTP fundamentals — the request-response model¶

Client (browser/curl/Python) → HTTP Request → Server → HTTP Response → Client

Every request has: a method (GET/POST/PUT/DELETE), a URL, headers, and optionally a body. Every response has: a status code, headers, and a body.

curl — the terminal's HTTP client for testing APIs:

curl https://api.example.com/data                    # GET
curl -X POST -H "Content-Type: application/json" \
     -d '{"key": "value"}' \
     https://api.example.com/data                   # POST with JSON

The exam connection: the entire HTTP status-code family (200/401/403/404/429/500) lives here — tested in every paper.

Chrome DevTools — seeing what the browser does¶

What it's for: inspecting network requests, viewing JavaScript console output, examining the DOM, profiling performance.

The exam connection: DevTools is where you'd see a CORS error in real life — the browser console shows the blocked request. Knowing it exists connects the theory to the debugging.

→ GA0: use-devtools · GA1: use-devtools

Git basics — the daily commands¶

The bridge course covers the same git workflow as Week 1, at a gentler pace:

git init              # start tracking a directory
git add .             # stage everything
git commit -m "msg"   # save a snapshot
git push origin main  # upload to GitHub
git pull origin main  # download and merge

Full treatment with the exam questions: Week 1 — Git.

What GA0 tests (the practice questions)¶

GA0 has 25 questions covering a mix of old-style fundamentals and ET-flavored theory: - Chart reading (axis-scale manipulation, what does this chart claim) - Binary evaluation rubric (how to grade a model's output) - Property-based testing (Hypothesis invariants — T1-AN Q10) - Unicode, CSS selectors, JSON sorting, SQL averages (classic TDS GA1 topics) - DevTools, GitHub, GitHub Actions (tool identification)

GA0 is effectively a mini-ET in disguise — its chart-reading and property-based-testing questions match the theory-question style the exam uses.