Educational Cards
Learn from video content, text, and interactive tasks
Filters
Reductions, statistics, and views vs copies
The real reason to switch is vectorisation : you write whole-array expressions and NumPy does the...
Broadcasting and boolean masks
Broadcasting is NumPy's rule for combining arrays of different shapes. When the shapes are...
Parsing rows and the bool('False') trap
Now combine the two ideas: a function that turns one raw row of strings into properly typed values....
Measurement scales and your first function
Everything read from a CSV is a string, so before you can compute you must parse each value into...
Why loops first, and the length pitfall
Every operation here is a Python-level loop that pays a small cost for each element. On three...
Lists as vectors: scaling and the dot product
A column of numbers — prices, scores, temperatures — is a vector , and in plain Python a vector is...
Print, input, and turning text into numbers
Python is the language most data scientists reach for first, and like any language you begin by...
Type hints and a numeric helper
As projects grow, functions become the way you organise them. A function with type hints states its...
Choosing charts and headless plotting
Four charts do most of the everyday work, and each answers a different question: - a histogram...
Reading JSON and the many faces of missing
Most web data arrives as JSON , a text format of nested objects and arrays that maps cleanly onto...
Project paths and feature pipelines
The same instinct produces small utilities that keep a project tidy. A recurring nuisance is file...
Every metric is an estimate; confidence intervals
Every metric is an estimate from a finite sample, and real decisions hinge on whether a difference...