Functions & Classes

The primary tool for reusable code: the function.

Benefits

• Modularity: break problems into small pieces

• Abstraction: hide the “how,” expose the “what”

• Testability: verify functions in isolation

• Collaboration: team members build different functions

Good design

• Descriptive verb-noun name (calculate_mean, not do_math)

• Single responsibility: one function, one job

• No global variables: pass everything as arguments

More advanced codebases can benefit greatly from a more versatile structural coding pattern: the class.

Benefits

• Encapsulation: bundle data and behavior

• State management: retain data across operations

• Inheritance: extend and reuse existing structures

Good design

• Descriptive noun name (PascalCase, e.g., DataProcessor)

• High cohesion: methods tightly related to class data

• Low coupling: minimized dependencies on external components