Connection lifecycle management in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a FastAPI app with a startup event handler.

FastAPI

from fastapi import FastAPI

app = FastAPI()

@app.on_event("[1]")
async def startup_event():
    print("App is starting up")

Drag options to blanks, or click blank then click option'

Astartup

Bon_startup

Con_start

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect event names like 'start' or 'on_start'.

Forgetting to use the @app.on_event decorator.

The correct decorator for startup events in FastAPI is @app.on_event("startup"). Here, the blank is filled with startup.

2fill in blank

medium

Complete the code to define a shutdown event handler in FastAPI.

FastAPI

from fastapi import FastAPI

app = FastAPI()

@app.on_event("[1]")
async def shutdown_event():
    print("App is shutting down")

Drag options to blanks, or click blank then click option'

Astop

Bstart

Cshutdown

Dclose

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'stop' or 'close' instead of 'shutdown'.

Not using the @app.on_event decorator.

The correct event name for shutdown in FastAPI is "shutdown". This decorator runs the function when the app is closing.

3fill in blank

hard

Fix the error in the code to properly close a database connection on shutdown.

FastAPI

from fastapi import FastAPI

app = FastAPI()
db = None

@app.on_event("startup")
async def connect_db():
    global db
    db = await connect_to_db()

@app.on_event("[1]")
async def close_db():
    await db.close()

Drag options to blanks, or click blank then click option'

Astart

Bclose

Cstop

Dshutdown

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'close' or 'stop' instead of 'shutdown'.

Not awaiting the close method.

The shutdown event must be named "shutdown" to properly register the close_db function to run when the app stops.

4fill in blank

hard

Fill both blanks to create a dependency that opens and closes a database connection per request.

FastAPI

from fastapi import FastAPI, Depends

app = FastAPI()

async def get_db():
    db = await connect_to_db()
    try:
        yield db
    finally:
        await db.[1]()

@app.get("/items")
async def read_items(db = Depends([2])):
    return await db.fetch_items()

Drag options to blanks, or click blank then click option'

Aclose

Bconnect

Cget_db

Ddisconnect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'disconnect' instead of 'close'.

Passing 'connect' instead of the dependency function to Depends.

The database connection should be closed with close() in the finally block. The dependency function is get_db, which is passed to Depends.

5fill in blank

hard

Fill all three blanks to create a FastAPI app that manages a resource with startup and shutdown events and a route using that resource.

FastAPI

from fastapi import FastAPI

app = FastAPI()
resource = None

@app.on_event("[1]")
async def startup():
    global resource
    resource = await open_resource()

@app.on_event("[2]")
async def shutdown():
    await resource.[3]()

Drag options to blanks, or click blank then click option'

Astartup

Bshutdown

Cclose

Dopen

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up event names.

Using 'open' instead of 'close' to release the resource.

The startup event is named "startup", the shutdown event is "shutdown", and the resource is closed with close().