README.md

Module 028: Copying Objects (Shallow vs Deep Copy)

Phase: 3. Data Structures
Estimated Time: 1.5 hours
Milestone: No

Overview

Understand the difference between references, shallow copies, and deep copies in Python, and when each is appropriate.

Topics

• Reference vs copy
• .copy() method on lists and dicts
• copy.copy() (shallow copy)
• copy.deepcopy() (deep copy)
• Why deep copy matters for nested structures
• Assignment vs copy

Learning Objectives

• Distinguish between assignment (reference) and copying
• Use .copy() on lists and dictionaries
• Use copy.copy() and copy.deepcopy()
• Explain when shallow copy is insufficient
• Avoid mutation bugs with nested structures

Prerequisites

• Modules 000–027

Next Module

Module 029: Choosing the Right Data Structure