Python and Flask Tutorial

A Web Application with Python version 3.12.1 and Flask version 3.0.0

Last updated

Download Python from the official website Python
Make sure that you have installed Python and Flask by the commands in Powershell: "python --version" or "flask --version"
Download the the Python extension for Visual Studio Code which automatically include the Pylance extionsion
Download / fork this Flask Starter Web App from my GitHub
Create the virtual envirement ".venv" for the Flask Web App by Powershell or by VS Code
Virtual Enviroment by VS Code: "View - Command Palette - Python Create Enviroment"

Right click the local folder with the Flask Web App and open Powershell
Run "flask run" and type "http://127.0.0.1:5000/" in your Browser and check the site is loaded
If ".flaskenv" is not found run "pip install python-dotenv" and run "flask run" again
You can also run the Flask Web App by run "flask --app api/index run" which point directly at the Flask entry file

The folder ".vscode" includes the launch file for local development / debug by VS Code. Note: For some reason debug throw an exeption, but without chrashing and you can see the changes by f5. However, just "run without debug" and you will notise that the debug is still on and hit f5 for see the changes. This way you will avoid the exception
Open a Browser and type "http://127.0.0.1:5000/" to see the site
Make a change in a file and type f5 or refresh the Browser to see the change

To debug from outside VS Code right click at the rootfolder with the repository forked from GitHub, open Powershell and type: "flask run --debug" which should use the settings in the .flaskenv file.
By using "flask run --debug" you could get promted to do: "pip install python-dotenv" for make things work
Check that the package "python-dotenv" is installed by running "pip list" to display a package list
Now you should be able to start in debug mode just by typing "flask run"
Open a Browser and type "http://127.0.0.1:5000/" to see the site
Make a change in a file and type f5 or refresh the Browser to see the change

Make sure to have both a GitHub and a Vercel Account
Create a repository with the Web App Starter at GitHub
Log in to Vercel and select the GitHub repository with your Web App Starter and follow the instructions
The vercel.json file will be used at Vercel Serverless Functions
Commit and sync your changes to GitHub which will create an automated Deployment to Vercel
Check that your site is online at Vercel "your-repository-name.vercel.app"

"python --version" => Display the installed Python version
"flask --version" => Display the version of installed Python, Flask and Werkzeug
"flask run" => Run the Flask Web App
"flask --app api/index run" => Run the Flask Web App which point directly at the Flask entry file
"flask run --debug" => Run the Flask Web App in Debug mode - Show the file cnage by hitting f5
"pip install package name" => "pip install python-dotenv" => Installing a package
"pip uninstall package name" => "pip uninstall python-dotenv" => Removing a package
"pip list" => Display a list of the installed packages
"pip freeze requirements.txt" => Create a requirements.txt file with the installed packages