Flask is a micro web framework written in Python. It has no database abstraction layer, form validation, or any other components where pre-existing third-party libraries provide common functions. However, Flask supports extensions that can add application features as if they were implemented in Flask itself. Extensions exist for object-relational mappers, form validation, upload handling, various open authentication technologies and several common framework related tools. Extensions are updated far more frequently than the core Flask program.
pip install flask
A blueprint is an object that defines a collection of views, templates, static files and other elements that can be applied to an application. The killer use-case for blueprints is to organize our application into distinct components. However, a Flask Blueprint needs to be registered in an application before you can run it. Once it's done, it extends the application with the contents of the Blueprint.