Flask Database Website
This is a set of resources that cover 3 internals and is implemented in Python. The covered internal are:
Expectations/Requirements
This set of resources expects a basic understanding of Python programming.
Software
There are 2 potential ways to do this course. The first uses your own device and runs everything locally, the alternative is to ue an online IDE such as GitHub CodeSpaces (recommended) or GitPod.io.
General Requirements
- GitHub Account - this is used to store a history of your code and also make sure you don't lose it.
Device Requirements
If you are doing local development you will need a modern computer running either Linux, Windows 10/11 or MacOS (Chromebooks do not work).
- Python v3.8+ (the latest version is always recommended as its faster and has better error messages)
- SQLiteStudio is used to edit your SQLite Database
- An IDE or editor - We recommend Visual Studio Code but people have been known to use Atom and even IDLE or VIM.
Online IDE
If you are using an online IDE the main thing you need is your GitHub account as everything should be handled for you.
You will also need:
- SQLiteStudio is used to edit your SQLite Database
Getting Setup
To setup your python project you should follow the guide here and install these dependencies:
- flask (Web server)
Basic Flask
To start your flask journey we can create a basic program and save it to a python file (we recommend calling it main.py). A basic Flask program is below:
from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello():
return "Hello World!"
if __name__ == "__main__":
app.run(debug=True)
What does this all mean????
There is a lot going on here already and its only a basic program but while it might look confusing it doesn't do too much. We have a walkthrough of each line below:
from flask import Flask
app = Flask(__name__)
This imports the Flask library and creates a new Flask application. The __name__ variable is used to determine the path of the application. This is used to find templates and static files.
@app.route("/")
def hello():
return "Hello World!"
This is a decorator that is used to tell Flask what URL should trigger the function. In this case we are telling Flask that when the user goes to the root of the website (e.g. https://example.com/) it should run the hello() function. The hello() function returns the string "Hello World!" which is then displayed to the user.
if __name__ == "__main__":
app.run(debug=True)
This is the last line of the program and is used to start the Flask application. The debug=True argument is used to tell Flask to restart the application when a file is changed. This is useful for development but should be removed when the application is deployed.
If you run your program python main.py you should see something like this:
* Serving Flask app 'main'
* Debug mode: on
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
* Running on http://127.0.0.1:5000
Press CTRL+C to quit
* Restarting with stat
* Debugger is active!
* Debugger PIN: 994-410-986
If you visit http://127.0.0.1:5000 you should be able to see you webpage.
Expanding on basic Flask
Multiple Routes
With Flask you can have multiple routes in your application and each route will do something different. For example, we can add a new route that will display a different message when the user visits it. We can do this by adding the following code to our main.py file:
@app.route("/fact")
def hello():
facts = ["The first computer bug was an actual bug", "The first computer virus was created in 1983", "The first computer virus was created in 1983"]
return random.choice(facts)
This can now be accessed at http://127.0.0.1:5000/fact. You can add as many routes as you want to your application and flask will use the string in the decorator to determine which function to run.