Uvicorn server basics in FastAPI - Mini Project: Build & Apply

Uvicorn Server Basics with FastAPI

📖 Scenario: You want to create a simple web server that can respond to visitors with a friendly message. This server will use FastAPI, a popular Python framework, and run on Uvicorn, a fast server for Python web apps.

🎯 Goal: Build a basic FastAPI app and run it using Uvicorn. The app will have one route that returns a welcome message when accessed.

📋 What You'll Learn

Create a FastAPI app instance named app

Define a GET route at path / that returns a JSON message

Set a variable host to "127.0.0.1"

Set a variable port to 8000

Use uvicorn.run() to start the server with the app, host, and port

💡 Why This Matters

🌍 Real World

Web developers use FastAPI with Uvicorn to quickly build and run web APIs that respond to user requests.

💼 Career

Knowing how to set up and run a FastAPI app with Uvicorn is essential for backend developers working with modern Python web frameworks.

1

Create the FastAPI app instance

Import FastAPI from fastapi and create an app instance called app.

FastAPI

from fastapi import FastAPI

# Create the FastAPI app instance named app
# Your code here

Need a hint?

Use app = FastAPI() to create the app instance.

2

Add a GET route for the root path

Define a GET route on app for path "/" that returns a dictionary with the key "message" and value "Hello, Uvicorn!".

FastAPI

from fastapi import FastAPI

app = FastAPI()

# Define a GET route for path "/" that returns {"message": "Hello, Uvicorn!"}
# Your code here

Need a hint?

Use @app.get("/") decorator and define a function that returns the dictionary.

3

Set host and port variables

Create two variables: host set to "127.0.0.1" and port set to 8000.

FastAPI

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"message": "Hello, Uvicorn!"}

# Set host to "127.0.0.1" and port to 8000
# Your code here

Need a hint?

Assign the string "127.0.0.1" to host and the number 8000 to port.

4

Run the app with Uvicorn

Import uvicorn and use uvicorn.run() to start the server with app, host, and port.

FastAPI

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"message": "Hello, Uvicorn!"}

host = "127.0.0.1"
port = 8000

# Import uvicorn and run the app with uvicorn.run(app, host=host, port=port)
# Your code here

Need a hint?

Use uvicorn.run(app, host=host, port=port) to start the server.