Folder structure patterns in FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

Why is organizing your FastAPI project into folders important?

It helps keep code clean, easy to find, and simple to maintain as the project grows, just like organizing files in labeled folders on your computer.

beginner

What is the purpose of the app/main.py file in a FastAPI project?

It usually contains the main FastAPI app instance and the code to start the server, acting like the front door to your application.

beginner

What kind of code do you put inside the app/api/ folder?

You put your route definitions and API endpoint logic here, similar to how a restaurant menu lists all the dishes you can order.

intermediate

Why separate models, schemas, and services into different folders?

Separating them keeps your code organized by role: models handle data structure, schemas handle data validation, and services handle business logic, like having different drawers for tools, papers, and gadgets.

intermediate

What is a common folder structure pattern for a medium-sized FastAPI project?

A typical pattern is: app/main.py, app/api/ for routes, app/models/ for database models, app/schemas/ for data validation, app/services/ for business logic, and app/core/ for config and utilities.

Which folder usually contains your API route definitions in a FastAPI project?

A app/models/

B app/core/

C app/api/

D app/tests/

The app/api/ folder is where you define your API routes and endpoints.

Where should you put your Pydantic schemas for data validation?

A app/schemas/

B app/services/

C app/api/

D app/models/

Pydantic schemas for validating and serializing data are typically placed in app/schemas/.

What is the role of the app/core/ folder?

A To keep database models

B To hold API route handlers

C To write unit tests

D To store configuration and utility functions

app/core/ usually contains configuration settings and helper utilities.

Why is it good to separate business logic into a services/ folder?

A To keep logic separate from routes and models for easier maintenance

B To store HTML templates

C To hold database migration files

D To write test cases

Separating business logic into services/ helps keep code clean and easier to update.

Which file usually starts the FastAPI application?

A app/services/auth.py

B app/main.py

C app/api/routes.py

D app/models/user.py

app/main.py typically creates the FastAPI app instance and runs the server.

Describe a simple folder structure for a FastAPI project and explain what each folder is for.

Think about separating code by its role to keep things organized.

Why is it helpful to separate your FastAPI code into folders like models, schemas, and services?

Consider how organizing your desk helps you find things faster.