Harry Percival has completed his second book, "Architecture Patterns with Python".
 So of course we talk about the book, also known as "Cosmic Python".
 We also discuss lots of testing topics, especially related to larger systems and systems involving third party interfaces and APIs.

Topics 

• Harry's new book, "Architecture Patterns with Python". a.k.a. Cosmic Python 
• TDD : Test Driven Development
• Test Pyramid
• Tradeoffs of different architectural choices
• Mocks and their pitfalls
• Avoiding mocks
• Separating conceptual business logic
• Dependency injection
• Dependency inversion
• Identifying external dependencies
• Interface adapters to mimize the exposed surface area of external dependencies
• London School vs Classic/Detroit School of TDD
• Testing strategies for testing external REST APIs

Links:

• Cosmic Python - Simple Patterns for Building Complex Applications
• Architecture Patterns with Python - on Amazon
• Harry Percival (@hjwp) / Twitter
• Bob Gregory (@bob_the_mighty) / Twitter
• vcrpy · PyPI
• Writing tests for external API calls
• Stop Using Mocks (for a while) - Harry's PyCon talk