Flask (web framework)
Developer(s) | Armin Ronacher |
---|---|
Initial release | April 1, 2010 |
Stable release | 2.0.1[1]
/ 21 May 2021 |
Repository | github |
Written in | Python |
Type | Web framework |
License | BSD |
Website | palletsprojects |
Flask is a micro web framework written in Python. It is classified as a microframework because it does not require particular tools or libraries.[2] 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.[3]
Applications that use the Flask framework include Pinterest and LinkedIn.[4][5]
History[]
Flask was created by Armin Ronacher of Pocoo, an international group of Python enthusiasts formed in 2004.[6] According to Ronacher, the idea was originally an April Fool's joke that was popular enough to make into a serious application.[7][8][9] The name is a play on the earlier Bottle framework.[7]
When Ronacher and Georg Brandl created[when?] a bulletin board system written in Python, the Pocoo projects Werkzeug and Jinja were developed.[10]
In April 2016, the Pocoo team was disbanded and development of Flask and related libraries passed to the newly formed Pallets project.[11][12]
Flask has become popular among Python enthusiasts. As of October 2020, it has second most stars on GitHub among Python web-development frameworks, only slightly behind Django,[13] and was voted the most popular web framework in the Python Developers Survey 2018.[14]
Components[]
The microframework Flask is part of the Pallets Projects (formerly Pocoo), and based on several others of them.
Werkzeug[]
Werkzeug (German for "tool") 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 2.7 and 3.5 and later.[15][16]
Jinja[]
Jinja, also by Ronacher, is a template engine for the Python programming language and is licensed under a BSD License. Similar to the Django web framework, it handles templates in a sandbox.
MarkupSafe[]
MarkupSafe is a string handling library for the Python programming language, licensed under a BSD license. The eponymous MarkupSafe type extends the Python string type and marks its contents as "safe"; combining MarkupSafe with regular strings automatically escapes the unmarked strings, while avoiding double escaping of already marked strings.
ItsDangerous[]
ItsDangerous is a safe data serialization library for the Python programming language, licensed under a BSD license. It is used to store the session of a Flask application in a cookie without allowing users to tamper with the session contents.
Features[]
- Development server and debugger
- Integrated support for unit testing
- RESTful request dispatching
- Uses Jinja templating
- Support for secure cookies (client side sessions)
- 100% WSGI 1.0 compliant
- Unicode-based
- Extensive documentation
- Google App Engine compatibility
- Extensions available to enhance features desired
Example[]
The following code shows a simple web application that displays "Hello World!" when visited:
from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello() -> str:
return "Hello World"
if __name__ == "__main__":
app.run(debug=False)
See also[]
References[]
- ^ "Version 2.0.1". 21 May 2021. Retrieved 22 May 2021.
- ^ "Flask Foreword". Archived from the original on 2017-11-17.
- ^ "Flask Extensions". Archived from the original on 2018-05-17.
- ^ What challenges has Pinterest encountered with Flask?
- ^ Rachel Sanders: Developing Flask Extensions - PyCon 2014
- ^ "Pocoo Team". Archived from the original on 2018-03-15.
- ^ Jump up to: a b Ronacher, Armin. "Opening the Flask" (PDF). Archived from the original (PDF) on 2016-12-17. Retrieved 2011-09-30.
- ^ Ronacher, Armin (3 April 2010). "April 1st Post Mortem". Armin Ronacher's Thoughts and Writings. Archived from the original on 2018-05-14. 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.
- ^ "History". Pocoo Team. Archived from the original on 2017-11-19. Retrieved 2015-03-25.
- ^ Ronacher, Armin (2016-04-01). "Hello Pallets Users". The Pallets Projects. Retrieved 2021-05-08.
- ^ "Pocoo". www.pocoo.org. Retrieved 2021-05-08.
- ^ "Python libraries by GitHub stars". Github. Retrieved 2020-01-27.
- ^ "Python Developers Survey 2018". www.jetbrains.com. 2018-11-01.
- ^ Ronacher, Armin. "Werkzeug The Python WSGI Utility Library". palletsprojects.com. Retrieved 27 May 2018.
- ^ Ronacher, Armin. "Installation, Python Version". palletsprojects.com. Retrieved 20 April 2020.
External links[]
- Free software programmed in Python
- Python (programming language) web frameworks
- Software using the BSD license