Command line, Git, Python, and environments
Make your program run from a clean copy, not just your own folder.
Reviewed: 2026-10-03
Source-based teaching example · Fictional data
Narration: Microsoft Mark · locally synthesized

00:00:00.000 — What you will learn

Make your program run from a clean copy, not just your own folder.

Visual description:
Make your program run from a clean copy, not just your own folder.

00:00:07.125 — The idea

Record the setup and dependency versions. Test valid records and records that must fail. Ask whether another person can repeat the run using your instructions.

Visual description:
Record the setup and dependency versions. Test valid records and records that must fail. Ask whether another person can repeat the run using your instructions.

00:00:20.625 — One useful term

Dependency. Other software your program needs to run.

Visual description:
Other software your program needs to run.

00:00:27.542 — A worked example

The CSV exercise normalizes records and checks missing IDs and duplicates. A peer starts from an empty directory and runs the documented test command. That run provides evidence beyond “it worked on my machine.”

Visual description:
The CSV exercise normalizes records and checks missing IDs and duplicates. A peer starts from an empty directory and runs the documented test command. That run provides evidence beyond “it worked on my machine.”

00:00:44.833 — Your turn to think

If the clean copy fails, should you immediately rewrite the program? Pause and decide before continuing.

Visual description:
If the clean copy fails, should you immediately rewrite the program?
Pause the video if you need more time.

00:01:02.625 — Why this answer works

First compare the Python version and working directory. Passing tests does not separately prove that dependencies come from trusted sources.

Visual description:
First compare the Python version and working directory. Passing tests does not separately prove that dependencies come from trusted sources.

00:01:14.292 — Check 1

Record exact setup and test commands.

Visual description:
Record exact setup and test commands.

00:01:19.917 — Check 2

Test valid and invalid records.

Visual description:
Test valid and invalid records.

00:01:25.167 — Check 3

Check dependency origin as well as behavior.

Visual description:
Check dependency origin as well as behavior.

00:01:30.917 — Now try a different case

Open the lesson and try its different practice case. Use every check in the full task. Watching alone does not mark the lesson complete.

Visual description:
Open the lesson
Try the new case
Check and revise
The full task and its requirements are in the linked lesson.