Episode 9 — The Pitch Deck
Programming with Python · Tutorial 09
The pitch meeting is Friday, and the investor gave one instruction: “Bring me charts I can’t argue with.” Last week you turned the data room into honest numbers; this week those numbers have to be seen. Same eighty orders, same orders DataFrame, now with a picture attached. You’ll draw a line for revenue over time, pick the right chart for categories, distributions and relationships, and (the real skill) refuse to draw a dishonest one. Kevin has already “built the deck”, and his growth slide is a lie wearing a nice axis. Your job is to supervise: catch the chart you can argue with before the investor does.
Work on the notebook
Open in browser (recommended): runs entirely on your machine, in this tab: no account, no installation, and after it loads no internet is needed.
This lab loads pandas and matplotlib, both fetched over the network the first time. If the notebook fails to boot with a network error, or the first cell that imports one of them complains it can’t be imported, reload the page once (Cmd/Ctrl + R). That almost always fixes it.
Your progress lives in this browser tab. If you reload the page (Cmd/Ctrl + R) your work is still there. But if you close the tab and open the link again later, you start from a clean notebook. There is no cross-device sync in the browser, and clearing browser data or private mode also wipes it.
So: download your .py before you leave (menu → Download → Download Python code). That download is the only guaranteed copy. Handing in files works exactly like this in the checkpoints, so you get to practice the motion every week. Note: a downloaded .py is for submission and backup. You can’t upload it back into the browser editor.
Open in molab: marimo’s free cloud (account required). Your copy saves to your account and reopens on any device. Choose this if you know you’ll switch computers or want to be certain nothing is lost. Optional: nothing graded ever requires it.