Django and Flask: Best Practices for Web Application Layouts using python

Python is indeed flexible in its application layouts, which can be both a blessing and a challenge, especially for new developers. Here’s a breakdown of some common Python application layouts across different use cases, such as command-line applications, one-off scripts, installable packages, and web applications.

Command-Line Application Layouts

1. One-Off Script

For simple scripts that don’t require installation or dependencies:

helloworld/
│
├── .gitignore
├── helloworld.py
├── LICENSE
├── README.md
├── requirements.txt
├── setup.py
└── tests.py

helloworld.py: The main script.
LICENSE: Specifies the licensing.

README.md: Provides documentation for the application.
requirements.txt: Lists dependencies.
setup.py: Handles installation.

tests.py: Contains tests for the script.

2. Installable Single Package

When you have additional helper modules and want to package your application:

helloworld/
│
├── helloworld/
│   ├── __init__.py
│   ├── helloworld.py
│   └── helpers.py
│
├── tests/
│   ├── helloworld_tests.py
│   └── helpers_tests.py
│
├── .gitignore
├── LICENSE
├── README.md
├── requirements.txt
└── setup.py

helpers.py: Contains supporting functionality.

helloworld/init.py: Marks helloworld as a package.
tests/: Organized structure for testing various modules.

3. Application with Internal Packages

For larger applications with internal packages:

helloworld/
│
├── bin/
│
├── docs/
│   ├── hello.md
│   └── world.md
│
├── helloworld/
│   ├── __init__.py
│   ├── runner.py
│   ├── hello/
│   │   ├── __init__.py
│   │   ├── hello.py
│   │   └── helpers.py
│   │
│   └── world/
│       ├── __init__.py
│       ├── helpers.py
│       └── world.py
│
├── data/
│   ├── input.csv
│   └── output.xlsx
│
├── tests/
│   ├── hello/
│   │   ├── helpers_tests.py
│   │   └── hello_tests.py
│   │
│   └── world/
│       ├── helpers_tests.py
│       └── world_tests.py
│
├── .gitignore
├── LICENSE
└── README.md

bin/: Holds executable scripts.
docs/: Stores project documentation.
data/: Contains input/output files.

tests/: Structured similarly to the application’s package structure for organized testing.

Web Application Layouts

1. Django Project Layout

Django is more opinionated, with a predefined project and app structure:

project/
│
├── project/
│   ├── __init__.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
│
└── manage.py

After adding apps to a Django project, the structure grows:

app/
│
├── migrations/
│   └── __init__.py
│
├── __init__.py
├── admin.py
├── apps.py
├── models.py
├── tests.py
└── views.py

2. Flask Project Layout

Flask doesn’t enforce a strict structure, but a common layout might look like:

project/
│
├── app/
│   ├── __init__.py
│   ├── routes.py
│   ├── models.py
│   └── static/
│   └── templates/
│
├── config.py
├── run.py
├── requirements.txt
└── tests/

app/: Contains the core of your Flask application.
static/ and templates/: For CSS, JavaScript, and HTML templates.

config.py: Configuration settings.
run.py: The entry point of the application.