Introduction to Dictionaries

INTERACTIVE CHEAT SHEET

The Concept

A dictionary in Python is a mutable, ordered (as of Python 3.7) collection of key-value pairs. Instead of using numerical indices (like 0, 1, 2) to access elements like lists do, dictionaries use unique "keys" to map to specific "values". This makes retrieving, adding, and modifying data incredibly fast.

Key Points

Dictionaries are created using curly braces {} containing key: value pairs.
Access elements using their unique key inside square brackets (e.g., my_dict["name"]).
Dictionaries are mutable; you can update values by re-assigning them to an existing key (e.g., my_dict["age"] = 26).

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Core Concept Mastery • Python Visual Series Module