Async generator dependencies in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define an async generator dependency in FastAPI.

FastAPI

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

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

Adb

Bconnect_to_db()

Cawait db

Ddb.close()

Attempts:

3 left

💡 Hint

Common Mistakes

Yielding the function call instead of the connection object.

Calling close() before yielding.

The async generator yields the database connection object db so it can be used by the route handler.

2fill in blank

medium

Complete the code to use the async generator dependency in a FastAPI route.

FastAPI

from fastapi import Depends, FastAPI

app = FastAPI()

@app.get("/items/")
async def read_items(db = Depends([1])):
    return {"db_status": str(db)}

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

Aconnect_to_db

Bget_db

Cdb.close

Dyield_db

Attempts:

3 left

💡 Hint

Common Mistakes

Using the connection function instead of the dependency function.

Trying to call the dependency instead of passing it to Depends.

The route uses Depends(get_db) to inject the async generator dependency.

3fill in blank

hard

Fix the error in the async generator dependency by completing the code.

FastAPI

async def get_session():
    session = create_session()
    try:
        [1] session
    finally:
        await session.close()

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

Aawait

Breturn

Cyield from

Dyield

Attempts:

3 left

💡 Hint

Common Mistakes

Using return instead of yield in async generator.

Using await incorrectly before yield.

Async generator dependencies must use yield to provide the resource.

4fill in blank

hard

Fill both blanks to correctly define and use an async generator dependency with FastAPI.

FastAPI

async def get_resource():
    resource = await acquire_resource()
    try:
        [1] resource
    finally:
        await [2]

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

Ayield

Brelease_resource()

Cresource.close()

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using return instead of yield.

Calling close() instead of the async release function.

The async generator yields the resource and then releases it asynchronously in the finally block.

5fill in blank

hard

Fill all three blanks to create a FastAPI route that depends on two async generator dependencies.

FastAPI

async def get_db():
    db = connect_db()
    try:
        [1] db
    finally:
        db.close()

async def get_cache():
    cache = await connect_cache()
    try:
        [2] cache
    finally:
        await cache.disconnect()

@app.get("/data/")
async def get_data(db = Depends([3]), cache = Depends(get_cache)):
    return {"db": str(db), "cache": str(cache)}

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

Ayield

Cget_db

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using return instead of yield in generators.

Passing the wrong function to Depends.

Both async generators use yield to provide resources. The route depends on get_db and get_cache.