django-mptt-admin is a reusable Django application that provides an interactive tree view interface in the Django admin for models using django-mptt (Modified Preorder Tree Traversal). It enables drag-and-drop reordering, inline editing, adding child nodes, filtering within subtrees, and a grid view alternative. The backend is implemented as a Django admin mixin (`DjangoMpttAdminMixin`) that handles tree JSON serialization, move operations, and changelist customization. The frontend is a TypeScript integration layer that initializes a tree widget (using the tree-element library) and manages CSRF-protected AJAX move requests, loading spinners, and error handling. The repository includes a full example project with tests (unit, view, and Playwright), CI/CD pipelines, and internationalization for multiple languages. It is actively maintained, with recent major version 3.0.0 that replaced the previous jqTree library with a modern jQuery-free tree widget.
sqlalchemy_mptt is a Python library that provides SQLAlchemy mixins for implementing Modified Preorder Tree Traversal (MPTT) with SQLAlchemy models. It automatically maintains tree structure through SQLAlchemy event listeners, handling insert, update, and delete operations while preserving tree integrity. The library supports multi-tree scenarios, various primary key types, and provides methods for tree traversal, drilldown operations, and path-to-root queries. The architecture centers around the BaseNestedSets mixin class that adds tree-specific columns and methods to SQLAlchemy models, complemented by a TreesManager that handles SQLAlchemy events to automatically maintain lft, rgt, level, and tree_id attributes. The library demonstrates strong engineering practices with a compatibility layer for SQLAlchemy versions, comprehensive test suite, and active maintenance with recent support for SQLAlchemy 2.0 and modern Python versions.