Python
Beginner
What is Dictionary?
A built-in data structure that stores key-value pairs with O(1) average lookup time using hash tables.
Python dictionaries (dict) are mutable, unordered collections of key-value pairs. Keys must be hashable (strings, numbers, tuples). Access values with dict[key] or dict.get(key, default).
Since Python 3.7, dictionaries maintain insertion order. Common methods include .keys(), .values(), .items(), .update(), and .pop(). Dictionary comprehensions provide concise creation syntax.
