Flask (web framework)
|Initial release||April 1, 2010|
Flask is a micro web framework written in Python. It is classified as a microframework because it does not require particular tools or libraries. 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 regularly than the core Flask program.
In 2004, Pocoo was formed as an international group of Python enthusiasts. Flask was created by Armin Ronacher of Pocoo:
The microframework Flask is based on the Pocoo projects Werkzeug and Jinja2.
Werkzeug is a utility library for the Python programming language, in other words a toolkit for Web Server Gateway Interface (WSGI) applications, and is licensed under a BSD License. Werkzeug can realize software objects for request, response, and utility functions. It can be used to build a custom software framework on top of it and supports Python 2.6, 2.7 and 3.3.
Jinja is a template engine for the Python programming language and is licensed under a BSD License also by Ronacher. Similar to the Django web framework, furthermore it provides that templates are evaluated in a sandbox.
- 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()
- "Flask Foreword".
- "Flask Extensions".
- What challenges has Pinterest encountered with Flask?
- Rachel Sanders: Developing Flask Extensions - PyCon 2014
- Community web page for Flask
- "Pocoo team".
- Ronacher, Armin. "Opening the Flask" (PDF). Retrieved 2011-09-30.
- Ronacher, Armin (3 April 2010). "April 1st Post Mortem". Armin Ronacher's Thoughts and Writings. Retrieved 2015-07-25.
- "Denied: the next generation python micro-web-framework (April Fools page)". Archived from the original on 2011-09-04. Retrieved 2011-09-30.
- "Pocoo History".
- "Python libraries by GitHub stars".
- Ronacher, Armin. "Werkzeug The Python WSGI Utility Library". palletsprojects.com. Retrieved 27 May 2018.