LEGB Namespaces & Package Namespaces Differences

Namespace Packages in Python (Explicit vs Implicit)

In addition to runtime namespaces (Local, Enclosing, Global, Built-in), Python also has the concept of namespace packages, which relate to how modules and sub-packages are organized on disk.

Implicit Namespace Package

A namespace package allows you to spread a single Python package across multiple directories or distributions. This is especially useful for large frameworks or plugin systems.

Explicit Namespace Package

An explicit namespace package uses an __init__.py file to mark a directory as a Python package. This traditional method supports:

• Code initialization inside __init__.py
• Relative imports
• Bundling all submodules in one directory

please refer to the Understanding __init__ in Packages for more details on implicit and explicit namespace packages.

How Is This Different from LEGB Namespaces?

• LEGB defines how Python looks up variable names during execution (runtime scope resolution).
• Namespace packages define how Python locates and resolves modules across directories (import-time module resolution).
• Both are related to names, but they work at different phases: runtime vs import-time.

So, while runtime namespaces map names to objects in memory, package namespaces organize modules and their availability in your file system.