LIVE DEMO 4: Pandas on Jupyter
Assignment 4: https://classroom.github.com/a/-8Ns6P8q
See DLC: Advanced Data Cleaning for advanced topics:
In Lectures 1-3, you wrote Python scripts (.py files) that run top-to-bottom. Jupyter notebooks (.ipynb files) let you run code in any order, see results immediately, and mix code with documentation - perfect for data exploration and analysis. Think of .py files for production code and automation, and .ipynb files for interactive analysis and storytelling with data.
Jupyter notebooks provide an interactive environment for data analysis, combining code execution with rich output display. They're essential for exploratory data analysis, prototyping, and sharing results with stakeholders.

Jupyter notebooks organize work into cells that can contain code or markdown. This structure enables iterative analysis and clear documentation of the analytical process.

I started off with countless problems. But now I know, thanks to COUNT(), that I have "#REF! ERROR: Circular dependency detected" problems.
Reference:
Shift+Enter (run and advance), Ctrl+Enter (run and stay)