It appears that it's not an actual "sheet"; but, a crowd-sourced book. From the GitHub page, if you click on https://www.pythoncheatsheet.org/ and scroll to the bottom of the page and click on "Contributing," you go to the page on how to contribute to the "book." Subsequent "pages," accessed from the lower right corner take you to "Basics" and Built-In Functions" and more. It's not a sheet,
No, you're not stupid, and maybe "cheet-sheet" is a little bit misleading...
Visit the website, linked in the readme of the repo, then select the hamburger menu at the top-left, then select a topic...