Merge pull request #692 from realpython/fastapi

Add materials for the "Get Started With FastAPI tutorial"

Author: brendaweles

crud-operations/crud_fastapi.py

@@ -1,10 +1,11 @@
 from crud_sql_alchemy import Bird, init_db
 from crud_sql_alchemy import Session as SessionLocal
-from fastapi import Depends, FastAPI, HTTPException
 from pydantic import BaseModel, ConfigDict
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
+from fastapi import Depends, FastAPI, HTTPException
+
 app = FastAPI()
 init_db()
 

fastapi-url-shortener/source_code_final/shortener_app/main.py

@@ -1,9 +1,10 @@
 import validators
-from fastapi import Depends, FastAPI, HTTPException, Request
-from fastapi.responses import RedirectResponse
 from sqlalchemy.orm import Session
 from starlette.datastructures import URL
 
+from fastapi import Depends, FastAPI, HTTPException, Request
+from fastapi.responses import RedirectResponse
+
 from . import crud, models, schemas
 from .config import get_settings
 from .database import SessionLocal, engine

fastapi-url-shortener/source_code_step_2/shortener_app/main.py

@@ -1,9 +1,10 @@
 import secrets
 
 import validators
+from sqlalchemy.orm import Session
+
 from fastapi import Depends, FastAPI, HTTPException, Request
 from fastapi.responses import RedirectResponse
-from sqlalchemy.orm import Session
 
 from . import models, schemas
 from .database import SessionLocal, engine

fastapi-url-shortener/source_code_step_3/shortener_app/main.py

@@ -1,7 +1,8 @@
 import validators
+from sqlalchemy.orm import Session
+
 from fastapi import Depends, FastAPI, HTTPException, Request
 from fastapi.responses import RedirectResponse
-from sqlalchemy.orm import Session
 
 from . import crud, models, schemas
 from .database import SessionLocal, engine

fastapi/README.md

@@ -0,0 +1,15 @@
+# Get Started With FastAPI
+
+This repository contains code snippets discussed in the associated tutorial [Get Started With FastAPI](https://realpython.com/get-started-with-fastapi/).
+
+## Installation
+
+The recommended way to install FastAPI is with the `[standard]` extra dependencies. This ensures you get all the tools you need for developing an API without having to hunt down additional packages later:
+
+```console
+$ python -m pip install "fastapi[standard]"
+```
+
+The quotes around `"fastapi[standard]"` ensure the command works correctly across different [terminals](https://realpython.com/terminal-commands/) and operating systems. With the command above, you install several useful packages, including the [FastAPI CLI](https://fastapi.tiangolo.com/fastapi-cli/) and [uvicorn](https://www.uvicorn.org/), an ASGI server for running your application.
+
+You can also use the `requirements.txt` file in this folder and run `python -m pip install -r requirements.txt` to install the standard dependencies of FastAPI.

fastapi/main.py

@@ -0,0 +1,53 @@
+from typing import Optional
+
+from pydantic import BaseModel
+
+from fastapi import FastAPI
+
+app = FastAPI()
+
+books = [
+    {"id": 1, "title": "Python Basics", "author": "Real P.", "pages": 635},
+    {
+        "id": 2,
+        "title": "Breaking the Rules",
+        "author": "Stephen G.",
+        "pages": 99,
+    },
+]
+
+
+class Book(BaseModel):
+    title: str
+    author: str
+    pages: int
+
+
+@app.get("/books")
+def get_books(limit: Optional[int] = None):
+    """Get all books, optionally limited by count."""
+    if limit:
+        return {"books": books[:limit]}
+    return {"books": books}
+
+
+@app.get("/books/{book_id}")
+def get_book(book_id: int):
+    """Get a specific book by ID."""
+    for book in books:
+        if book["id"] == book_id:
+            return book
+    return {"error": "Book not found"}
+
+
+@app.post("/books")
+def create_book(book: Book):
+    """Create a new book entry."""
+    new_book = {
+        "id": len(books) + 1,
+        "title": book.title,
+        "author": book.author,
+        "pages": book.pages,
+    }
+    books.append(new_book)
+    return new_book

fastapi/requirements.txt

@@ -0,0 +1,39 @@
+annotated-types==0.7.0
+anyio==4.10.0
+certifi==2025.8.3
+click==8.2.1
+dnspython==2.7.0
+email_validator==2.2.0
+fastapi==0.116.1
+fastapi-cli==0.0.8
+fastapi-cloud-cli==0.1.5
+h11==0.16.0
+httpcore==1.0.9
+httptools==0.6.4
+httpx==0.28.1
+idna==3.10
+Jinja2==3.1.6
+markdown-it-py==4.0.0
+MarkupSafe==3.0.2
+mdurl==0.1.2
+pydantic==2.11.7
+pydantic_core==2.33.2
+Pygments==2.19.2
+python-dotenv==1.1.1
+python-multipart==0.0.20
+PyYAML==6.0.2
+rich==14.1.0
+rich-toolkit==0.15.0
+rignore==0.6.4
+sentry-sdk==2.34.1
+shellingham==1.5.4
+sniffio==1.3.1
+starlette==0.47.2
+typer==0.16.0
+typing-inspection==0.4.1
+typing_extensions==4.14.1
+urllib3==2.5.0
+uvicorn==0.35.0
+uvloop==0.21.0
+watchfiles==1.1.0
+websockets==15.0.1

langchain-rag-app/source_code_final/chatbot_api/src/main.py

@@ -1,8 +1,9 @@
 from agents.hospital_rag_agent import hospital_rag_agent_executor
-from fastapi import FastAPI
 from models.hospital_rag_query import HospitalQueryInput, HospitalQueryOutput
 from utils.async_utils import async_retry
 
+from fastapi import FastAPI
+
 app = FastAPI(
     title="Hospital Chatbot",
     description="Endpoints for a hospital system graph RAG chatbot",

langchain-rag-app/source_code_step_5/chatbot_api/src/main.py

@@ -1,8 +1,9 @@
 from agents.hospital_rag_agent import hospital_rag_agent_executor
-from fastapi import FastAPI
 from models.hospital_rag_query import HospitalQueryInput, HospitalQueryOutput
 from utils.async_utils import async_retry
 
+from fastapi import FastAPI
+
 app = FastAPI(
     title="Hospital Chatbot",
     description="Endpoints for a hospital system graph RAG chatbot",

python-serialize/http-payload/fastapi-rest-api/main.py

@@ -1,9 +1,10 @@
 from datetime import datetime
 from uuid import UUID, uuid4
 
-from fastapi import FastAPI
 from pydantic import BaseModel, Field
 
+from fastapi import FastAPI
+
 app = FastAPI()