Topic 5. Built-in collections: lists, tuples, sets, dictionaries, and the collections module

Goal: learn to choose collections for practical problems, process nested lists and dictionaries, perform set operations, use Counter, defaultdict, and deque, and verify correct copying and handling of empty data.

Lecture contents

1. Sequences and lists — Why collections are useful · Sequences: indices and slices · Modifying lists and ordering
2. Comprehensions and tuples — Comprehensions and two-dimensional lists · Tuples and unpacking
3. Sets and dictionaries — Sets and hashability · Dictionaries: keys, values, and iteration
4. The collections module and choosing a structure — Specialized standard library collections · Choosing a structure and operation costs
5. Program examples and common mistakes — Program examples · Common mistakes and checking a solution

Practice and review

• Practice — 3 worked examples with complete code and output
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links