Nested Data Structures

Nested data structures are collections that contain other collections as their elements. This nesting can occur in multiple patterns: a list of dictionaries represents a table of records, similar to rows in a database. A dictionary with list values groups related items by category. A dictionary containing other dictionaries models hierarchical relationships like organizational structures or configuration settings. Understanding these patterns is essential because they mirror the structure of JSON data, database query results, and configuration files that you encounter daily in data engineering. The key insight is that Python allows any data structure to contain any other data structure. Lists can hold dictionaries, dictionaries can hold lists, and you can nest these combinations arbitraril