python-project-structure

Defining a public API in Python modules uses the __all__ list to explicitly declare which objects are public. This mechanism enforces clear module boundaries by restricting exported names, keeping internal implementation private while exposing a stable, maintainable interface.

The best way to organize tests and packaging files is to adopt a standard layout with a src/ directory for code, a tests/ directory for test placement, and pyproject.toml for packaging decisions. This separation ensures scalable, maintainable project architecture.

To define explicit public interfaces using __all__, assign a list of string names to __all__ in your module's __init__.py. This dictates exactly what gets imported when users use wildcard imports, enforcing explicit module boundaries and clean public APIs.

Yes, you can reorganize an existing Python codebase by flattening deep hierarchies into a maintainable directory structure. By establishing clear module boundaries and defining explicit public interfaces with __all__, you refactor for better module cohesion and scalable architecture.

You should avoid a flat directory structure when your Python project lacks distinct module boundaries or requires complex nested namespaces. If module cohesion is low and defining a clear public API with __all__ is impossible, a different packaging approach may be needed.