Topic 4. Exception handling and debugging programs

Goal: learn to distinguish errors, handle expected exceptions, create custom error types, log failure causes, and find logic errors using PyCharm and pdb.

Lecture contents

1. Error types and the exception hierarchy — Error types and diagnostic reports · The built-in exception hierarchy
2. Handling and raising exceptions — Execution order of try, except, else, and finally · Raising and propagating exceptions
3. Custom exceptions and exception groups — Custom exceptions and responsibility boundaries · Exception groups and notes
4. Validation, resources, and logging — Validation, invariants, and resource cleanup · Event logging
5. Debugging in PyCharm and pdb — Debugging a program in PyCharm · The pdb debugger and a method for finding errors · Common mistakes

Practice and review

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