Werkzeug
The comprehensive WSGI web application library
...Werkzeug doesn’t enforce any dependencies. It is up to the developer to choose a template engine, database adapter, and even how to handle requests. Includes an interactive debugger that allows inspecting stack traces and source code in the browser with an interactive interpreter for any frame in the stack. Includes a full-featured request object with objects to interact with headers, query args, form data, files, and cookies. Includes a response object that can wrap other WSGI applications and handle streaming data. Includes a routing system for matching URLs to endpoints and generating URLs for endpoints, with an extensible system for capturing variables from URLs. ...