Lab 1 — Meet the Shell and Run Your First Program¶

For instructors — outcome alignment

Unit 1's practice session. Covers MSU Denver CS 1050 objectives 6–8 at a formative level; aligns with ABET student outcomes SO-2 and SO-6, under the ACM/IEEE-CS CS2023 SDF + FPL knowledge areas. Part B is a deliberate PRIMM sequence (Predict–Run–Investigate–Modify; the final M, Make, is Checkpoint 1 — students build their own from scratch there); Part C carries the course-of-record written-communication thread. (Alignment only — not an accreditation claim. Full mapping in the outcomes map.)

Labs are where a unit's ideas get into your fingers. This one has exactly one goal: by the end, you've explored Python's shell and written and run a real program of your own. Work through the parts in order — each one leans on the last (steps, followed exactly and in order… sound familiar?).

Nothing here is graded on correctness — labs are practice. Get stuck? That's normal on your first lab, and it's what the room (and office hours) are for.

Before you start

This lab assumes Python is installed and working — run check_env.py and make sure the last line says PASS (the install guide gets you there, and the Using GitHub guide shows how to download course files). Everything else in the course depends on that PASS.

Part A — Ten minutes in the interactive shell¶

Open IDLE's shell (primer here if it's new to you) and try each of these with your own values — don't copy mine:

Type a number and press Enter. Then a decimal number. Then some text in quotes.
Create two variables about yourself with good descriptive names (the Unit 1 lesson is your reference), then type each name to see what comes back.
Ask Python for the type of each: type(your_variable_here).
Now break something on purpose: try text without quotes, or a variable name with a space in it. Read the error — you'll be seeing messages like this all semester, and they're friendlier than they look.

Part B — Predict, then run¶

Grab the starter file my_lab1.py and open it in IDLE's editor (not the shell — the primer covers the difference).

Predict: the file's comments contain a tiny finished program. Before you run anything, write down — on paper or in a comment — exactly what you think it will print, line by line.
Run it and compare against your prediction. Exactly right? Great — you just traced a program like the machine does. Different? Even better: figure out which line surprised you and why.
Make it yours: replace the example variables with four of your own (one int, one float, one str, one bool — descriptive names, please) and print each one.

Part C — Say it in your own words¶

At the bottom of my_lab1.py, in a comment (start the line with #), write 2–3 sentences for a friend who's never coded: what's the difference between a variable and its value? Use your own everyday example. (Yes, this is the same rep as the lesson's communicate prompt — explaining things clearly is a skill this course grades on later, so we start practicing now.)

Done looks like¶

check_env.py says PASS (the precondition)
You tried values, variables, and type(...) in the shell — including breaking it on purpose
Your my_lab1.py runs and prints your four variables
Your variable-vs-value explanation is in a comment at the bottom
Enrolled in a section? Turned in per your section's instructions. Self-learning? All the boxes above checked is done.