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Visual deck · 10 scenes · 20 animation beats
Pandas, visually
An animated tour of pandas: the anatomy of a DataFrame, Series, boolean masks, loc versus iloc, vectorisation, groupby, merge and rolling windows, on a small price table.
By Sitraka Forler · Lecturer, Durham Business SchoolUpdated 3 October 2026 About this site
A DataFrame is a table with an index, and almost every pandas error comes from forgetting the index. This deck draws the table, then animates what each operation does to it: a boolean mask keeps some rows, loc selects by label, iloc by position, groupby splits the table into piles and merge lines two tables up by a key.
The data is a few days of prices for three tickers, small enough to check every number by eye. That is deliberate: once you can predict the output on five rows, the same code works on five million.
How to drive it
- Click or tap anywhere, or press Space or the right arrow: one press is one animation beat, so you can narrate between reveals.
- Left arrow or right click goes back one beat. Escape leaves the deck.
- The position is kept in the address bar (#scene.beat), so a link lands on the exact beat you were showing.
The 10 scenes
- 1The anatomy of a DataFrame: index, columns, values
- 2A column is a Series, and a Series has an index too
- 3Boolean masks: a column of True and False that filters rows
- 4loc selects by label, iloc by position
- 5Vectorisation: one expression, every row, no loop
- 6groupby: split, apply, combine
- 7merge: lining up two tables by a key
- 8Rolling windows: a moving average, drawn as a sliding box
- 9The NaN that appears at the start of every rolling column
- 10The five lines you will write every day