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Deploying a Flask application

Introduction

Flask is a popular and lightweight web framework for Python. It's highly suitable for developers who want to make a standalone app. In this article, we'll cover how to deploy a Flask application for the world to see.

Prerequisites​

Before we begin, make sure you have the following:

  • Basic knowledge of Python.
  • A complete Flask app that you want to deploy.
  • Python and Flask installed on your local machine.
  • An account on a deployment platform (we will use Heroku for this tutorial)

Deploying a Flask Application

Step 1: Install Gunicorn​

Gunicorn 'Green Unicorn' is a Python WSGI HTTP Server for UNIX. It's a pre-fork worker model. This server will interface with our application, allowing it to speak 'web'. 

pip install gunicorn

Step 2: Install Heroku CLI​

The Heroku Command Line Interface (CLI) is a tool that wraps the Heroku Platform API, providing support for things like creating/renaming apps, running one-off dynos, taking backups, and configuring add-ons. 

brew install heroku/brew/heroku

Step 3: Login to Heroku​

Log in to your Heroku account. 

heroku login

Step 4: Create a Heroku App​

Creating an app on Heroku will prepare Heroku to receive your source code. 

heroku create your-app-name

Step 5: Create a Procfile​

Heroku apps include a Procfile that specifies the commands that are executed by the app on startup. 

echo "web: gunicorn app:app" > Procfile

Step 6: Initialize a Git Repository​

Initialize a git repository in a new or existing directory.

git init

Step 7: Commit Your Changes​

Heroku uses Git as a means of deploying your app. So you need to commit your changes before you can deploy.

git add .
git commit -m "Initial commit"

Step 8: Deploy Your App​

Now you can deploy your app to Heroku.

git push heroku master

Step 9: Open Your App​

Finally, you can now access your app in the browser.

heroku open

Conclusion

Congratulations, you've just deployed your first Flask application!

In this tutorial, we've covered how to deploy a Flask application on Heroku. This is just the beginning of what you can do with Flask and Heroku.

Remember, learning is a journey that never ends. So keep exploring, keep learning and keep implementing. If you run into any issues, don't hesitate to ask for help. Happy coding!