Flask (web framework)
|Initial release||April 1, 2010|
|Stable release||0.10.1 / June 14, 2013|
|Type||Web application framework|
As of 2015, the latest stable version of Flask is 0.10.1. Examples of applications that make use of the Flask framework are Pinterest, LinkedIn, as well as the community web page for Flask itself.
Flask is called a micro framework because it does not presume or force a developer to use a particular tool or library. 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.
Flask was created by Armin Ronacher of Pocoo which is an international group of Python enthusiasts formed in 2004. According to Armin, "It came out of an April Fool's joke but proved popular enough to make into a serious application in its own right." Flask is based on the Werkzeug WSGI toolkit and Jinja2 template engine, both of them Pocoo projects that were created when Ronacher and Georg Brandl were building a bulletin board system written in Python.
Despite the lack of a major release, Flask has become extremely popular among Python enthusiasts.
- Contains development server and debugger
- Integrated support for unit testing
- RESTful request dispatching
- Uses Jinja2 templating
- Support for secure cookies (client side sessions)
- 100% WSGI 1.0 compliant
- Extensive documentation
- Google App Engine compatibility
- Extensions available to enhance features desired
The following code shows a simple web application that prints "Hello World!":
from flask import Flask app = Flask(__name__) @app.route("/") def hello(): return "Hello World!" if __name__ == "__main__": app.run()
- "PyPI Flask". Python Package Index. 2015-03-25. Retrieved 2015-03-25.
- What challenges has Pinterest encountered with Flask?
- Rachel Sanders: Developing Flask Extensions - PyCon 2014
- Community web page for Flask
- "Flask Foreword".
- "Flask Extensions".
- "Pocoo team".
- Ronacher, Armin. "Opening the Flask" (PDF). Retrieved September 30, 2011.
- Ronacher, Armin (April 3, 2010). "April 1st Post Mortem". Armin Ronacher's Thoughts and Writings. Retrieved 25 July 2015.
- "Denied: the next generation python micro-web-framework (April Fools page)". Retrieved September 30, 2011.
- "Pocoo History".
- Flask website
- Flask documentation
- Project source code on Github
- Flask on PyPI
- Localization for Flask applications