chunloy/flask-workshop

demo

Introduction

This repo serves as an example to get started with Flask.

Getting started

1. Clone the repo on your local device: git clone git@github.com:chunloy/flask-workshop.git
2. Navigate into flask-workshop directory and create a virtual environment: cd flask-workshop && python -m venv .venv
3. Activate the virtual environment: source .venv/bin/activate
4. Install dependencies: pip3 install -r requirements.txt
5. Start the server in debugging mode: flask run --debug
6. Close the virtual environment when you're done: deactivate

Note: See section below for things I forgot to mention during the workshop.

Things not covered

1. The code may look slightly different from the recording due to small changes that I made, I'd recommend using this repo for reference. Changes involved returning data as is because they are valid return types by default.

2. You can get away with running flask run as is because the module is named app.py. If the module was named different, you'd have to specify the name in the command.

3. Making a request to get details for a single artist: see lines 95-98 in app.py

4. Making the POST request: curl -X POST localhost:5000/artists -d '{"artist_name":"notaaron","song_title":"song","featured_artist":"null","album_name":"hello, world","song_length":"4:00 PM"}' -H 'Content-type: application/json'

• -X specifies the type of request
• -d specifies the data in the request body
• -H specifies in the request header that the data is json

5. Try making a curl request with GET. This is my attempt at getting you all CLI Certified.

Flask workshop notes

Agenda

1. Prerequisites: install pip, virtualenv
2. Setting up your project: activate & deactivate virtualenv
3. Live demo: Setup Flask server + routing
4. Q & A

Prerequisites

These instructions assume you have Python 3.x installed.

Note: When running commands, be sure to use python3 and pip3, instead of python or pip, to avoid potential errors.

Installing pip

Run this command to install pip:

cd ~
python3 -m pip install --user --upgrade pip
python3 -m pip --version

Link installation docs: https://packaging.python.org/en/latest/guides/installing-using-pip-and-virtual-environments/

Installing virtualenv

Run this command to install virtualenv:

pip3 install virtualenv

link to package description: https://pypi.org/project/virtualenv/

Setting up your project

Why create a virtual environment? It installs packages only in the current directory. It's best to avoid installing packages globally to prevent version conflicts.

Note: The following commands are only vaild for Mac. If you're on Windows, you'll need to use a different set of commands.

1. Create a virtual environment by running this command:

python3 -m venv .venv

Note: you should see a folder named .venv in your project's root directory

2. Activate the virtual environment:

source .venv/bin/activate

Note: Make sure you do this BEFORE installing packages!

3. Run this command to close the virtual environment:

deactivate

Congratulations! You've set up a virttual environment and can safely install packages.

Tracking dependencies (optional, sort of)

After creating a project, you'll probably want to install and keep track of the packages you've installed. This will help other developers clone your project and install dependencies.

1. Create a text file in the project's root directory:

touch requirements.txt

2. Run this command to list your dependencies in the text file:

pip3 freeze > requirements.txt

Note: You'll want to run the above command every time you install new packages. Python doesn't keep track of them for you.