StartingFlask

Getting Started

1. Download the project on your computer. git clone https://github.com/sarvasvkulpati/StartingFlask or download the ZIP file

2. Go to the directory with the file: cd StartingFlask

3. Download the required packages: pip install -r requirements.txt

4. Run the project: export FLASK_APP=app.py && flask run

What is Flask?

The internet is based on something called the HyperText Transfer Protocol, or HTTP. That's the thing you see in your url all the time.

In essence, it's a set of rules that define how computers on the internet should communicate with each other.

Everytime you request for information on the internet, there's a 'web server' that serves that information. Flask makes it easy to write the code that powers these.

Starter Flask Application

Let's begin with the absolute minimum code required to create a flask server.

First, we import flask at the top of the file

from flask import Flask 

Next, we define our current file as our web application

app = Flask(__name__)

Then, we create our root page. The forward slash means that it exists at the base url.

@app.route('/', methods=['GET'])
def root():
    return "Root"

And finally, we create the main function

if __name__ == "__main__":
    app.run(debug=True)

Now, time to run the file from the terminal. There's two ways of doing this. The easy way is

python3 app.py

Though a better way to do it would be

export FLASK_APP=app.py 
export FLASK_DEBUG=1
flask run

You should see something like this:

You'll notice that it's being served on the url http://127.0.0.1:5000/ . That url is called your localhost, and it uses your computer to internally run a webserver.