flask/README.rst

Flask
=====

Flask is a lightweight `WSGI`_ web application framework. It is designed
to make getting started quick and easy, with the ability to scale up to
complex applications. It began as a simple wrapper around `Werkzeug`_
and `Jinja`_ and has become one of the most popular Python web
application frameworks.

Flask offers suggestions, but doesn't enforce any dependencies or
project layout. It is up to the developer to choose the tools and
libraries they want to use. There are many extensions provided by the
community that make adding new functionality easy.

.. _WSGI: https://wsgi.readthedocs.io/
.. _Werkzeug: https://werkzeug.palletsprojects.com/
.. _Jinja: https://jinja.palletsprojects.com/


Installing
----------

In a terminal, install or update Flask using `pip`_:

.. code-block:: text

    $ pip install -U Flask

.. _pip: https://pip.pypa.io/en/stable/getting-started/


A Simple Example
----------------

In a code editor or IDE of your choice, create a new file: app.py

Copy and paste the following code snippet into the app.py file.

.. code-block:: python

    # save this as app.py
    from flask import Flask

    app = Flask(__name__)

    @app.route("/")
    def hello():
        return "Hello, World!"

Save your file.

To execute the program, run the following command in a terminal:

.. code-block:: text

    $ flask run

You will receive the following message:

.. code-block:: text

    * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

You can open this address in an internet browser window to view your program.


Contributing
------------

For guidance on setting up a development environment and how to make a
contribution to Flask, see the `contributing guidelines`_.

.. _contributing guidelines: https://github.com/pallets/flask/blob/main/CONTRIBUTING.rst


Donate
------

The Pallets organization develops and supports Flask and the libraries
it uses. In order to grow the community of contributors and users, and
allow the maintainers to devote more time to the projects, `please
donate today`_.

.. _please donate today: https://palletsprojects.com/donate


Links
-----

-   Documentation: https://flask.palletsprojects.com/
-   Changes: https://flask.palletsprojects.com/changes/
-   PyPI Releases: https://pypi.org/project/Flask/
-   Source Code: https://github.com/pallets/flask/
-   Issue Tracker: https://github.com/pallets/flask/issues/
-   Code of Conduct: https://github.com/pallets/flask/blob/main/CODE_OF_CONDUCT.md
-   Website: https://palletsprojects.com/p/flask/
-   Twitter: https://twitter.com/PalletsTeam
-   Chat: https://discord.gg/pallets