Lesson 19 of 20 · 46 min · UG / professional
REPL editing, install notes, what next
History and tab completion make the prompt usable. After this track: the library docs for the job you have (pandas, Flask, microcontroller). Do not start with metaclasses.
School notice board
print() is how your program speaks.
You will be able to
- ✓ Use REPL history and tab completion as a scratchpad, not as the product
- ✓ Know what to install next: venv, pins, then the library for the job
- ✓ Pick pandas, Flask or kit docs next — not metaclasses
The prompt is a scratchpad with memory
Up-arrow history and tab completion make >>> usable on a campus PC. History is not a handover. When the line works, paste it into a .py file with a door. Tab completes names the interpreter already knows — it will not invent a GST policy.
IDLE, other editors and python -i script.py are nicer doors into the same engine. A nightly attendance job is still a file the scheduler launches, not a person sitting in a prompt.
What to install, then what to learn
Install current CPython from the lab image (or python.org), make a venv, pip only what this project pins. Then read the library docs for the job you have: pandas for tables, a small web framework for a form, microcontroller docs for the kit. Do not start with metaclasses, GIL trivia, or a new packaging tool every week.
This track’s next step is a tool someone else can run
The capstone is utilisation with a test. After that, copy laptop samples (os, requests, Decimal) into the venv and keep the sandbox habits: one formula, INFO lines, paise, UTF-8, PASS/FAIL.
Words that matter
- REPL history
- Previous lines at the prompt — scratch, not the product.
- Tab completion
- Fill a name the interpreter already knows.
- What next
- Job library docs after venv/pins — not a metaclass first.
Common mistakes
Avoid: Shipping a job that only works if someone is sitting in the prompt.
Do this: A .py file with a door, plus a README that names the venv.
Run it step by step
Each box is a real program. Press Run, change a number, Run again — the output must follow your code.
1. Step 1 — history as a list of lines
The analog of up-arrow. Still not the handover.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
2. Step 2 — install notes as data
What you would type after leaving this course.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
Example program — Scratch, then a door
Tab completion analog: names you already defined. Then print the launch line.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
Your turn — What next
Print a line that includes both pandas and venv.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
Self-assessment
Check your understanding before you mark the lesson complete.
Progress is stored in a browser cookie on this device.