My First Flask Web App: hello_world_flask

Description:

This is a basic web application that has a home page and an about page. The home page is routed to localhost:5000/ and localhost:5000/home. The about page is routed to localhost:5000/about. This is a basic proof of concept project that shows how to set up a python Flask web application for learning purposes.

Tutorial Being Followed: Corey Schafer Flask Tutorial - https://youtube.com/playlist?list=PL-osiE80TeTs4UjLw5MM6OjgkjFeUxCYH

Set Up:

Requirements:

1. Python
2. Pip
3. Flask
4. A text editor

Steps

1. Install Python

1. First check if python is installed or not by opening your terminal and typing the following command.

python --version

2. If python is properly installed your output should look like:

Python 3.8.5

3. If your version of python is earlier than this, you need to install the latest version of python.
4. Install python: https://www.python.org/downloads/

2. Install Pip

1. First check if pip is properly installed or not by opening your terminal and typing the following command:

pip --version

2. If python is properly installed your output should look like:

pip 20.3.3

3. If your version of pip is earlier than this, you need to install the latest version of pip.
4. Install Pip: https://pip.pypa.io/en/stable/installing/

3. Install Flask

1. First check if Flask is installed or not by opening your terminal and typing the following command.

flask --verison

2. If Flask is properly installed your output should look like:

Python 3.8.5
Flask 1.1.2
Werkzeug 1.0.1

3. If your version of flask is earlier than this, you need to install the latest version of flask.
4. Install Flask by running the following command:

pip install flask

5. Make sure Flask installed correctly by starting up python and importing flask
6. Open your terminal
7. start python by typing the following command:

python

3. Python should now start and your terminal will have a >>> infront of your cursor
4. Type the following command and hit enter

import flask

5. If this runs with no errors then flask is installed properly. If errors occur, flask needs to be properly installed. * See https://flask.palletsprojects.com/en/1.1.x/installation/ for further installation documentation.
6. Type the following command to exit the python editor in your terminal

exit()

Running The Web App

1. Clone this repo

2. Navigate to the directory (within the terminal) where you saved this repo

3. Set an environment variable to the file that will be the Flask application.

• In our case, run the following command for linux/mac

export FLASK_APP=HelloWorld_Flask.py

• For windows run

set FLASK_APP=HelloWorld_Flask.py

4. Run the application with the folowing command

flask run

5. If there are no errors, your output should look like the following:

* Serving Flask app "HelloWorld_Flask.py"
* Environment: production
  WARNING: This is a development server. Do not use it in a production deployment.
  Use a production WSGI server instead.
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

6. Open your web browser and navigate to the site provided in the final line of the output message

• You can also replace the 127.0.0.1 with localhost
• eg. instead of navigating to http://127.0.0.1:5000/ you can navigate to http://localhost:5000/