// the find
pallets/flask
The Python micro framework for building web applications.
Flask is a minimal WSGI web framework built on Werkzeug and Jinja2, aimed at developers who want routing and templating without a framework dictating project structure, database layer, or auth. It scales from a single-file script to a multi-module app via blueprints, but almost everything beyond routing is BYO extension.
The core is small enough to read in an afternoon — app.py, blueprints.py, and the sansio layer cover most of what you need to understand request handling end to end. The application factory + blueprint pattern lets a project grow from one file to a modular app without a rewrite. Decorator-based routing with app/request context globals keeps the common case (one request, one response) nearly boilerplate-free. The extension ecosystem (Flask-SQLAlchemy, Flask-WTF, Flask-JWT, etc.) is mature enough that you're rarely the first person to hit a given problem.
Still WSGI at its core — async view functions are supported syntactically but you don't get real async concurrency without switching to Quart or fronting it with gevent/eventlet workers. 'No enforced layout' means any app past toy size ends up reinventing the structure Django gives you by default, and that structure varies project to project. There's no built-in ORM, validation, or admin story, so a real app is actually 4-5 extensions you now own the version compatibility of. Signed-cookie sessions are the default session backend, and secret key rotation/production hardening is easy to get wrong if you don't read the deployment docs closely.