Depends function basics in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Depends function from FastAPI.

FastAPI

from fastapi import [1]

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

AResponse

BRequest

CDepends

DPath

Attempts:

3 left

💡 Hint

Common Mistakes

Importing Depends from fastapi.security instead of fastapi

Using Request or Response instead of Depends

The Depends function is imported from FastAPI to declare dependencies in your path operation functions.

2fill in blank

medium

Complete the code to declare a dependency function that returns a fixed string.

FastAPI

def get_token():
    return [1]

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A'token123'

B12345

Ctoken123

D"token123"

Attempts:

3 left

💡 Hint

Common Mistakes

Returning an unquoted string which causes a NameError

Returning a number instead of a string

The dependency function should return a string literal, so it must be quoted.

3fill in blank

hard

Fix the error in the FastAPI path operation to use Depends correctly.

FastAPI

from fastapi import FastAPI, Depends

app = FastAPI()

def get_token():
    return "token123"

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

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Aget_token()

BDepends(get_token)

CDepends(get_token())

Dget_token

Attempts:

3 left

💡 Hint

Common Mistakes

Calling the dependency function inside Depends

Passing the function without Depends

When declaring a dependency, you pass the function itself to Depends without calling it.

4fill in blank

hard

Fill both blanks to create a dependency that extracts a query parameter named 'q'.

FastAPI

from fastapi import Query

def get_query(q: str = [1]):
    return q

@app.get("/search")
async def search(query: str = [2]):
    return {"query": query}

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AQuery(None)

BDepends(get_query)

CQuery(...)

DDepends(Query)

Attempts:

3 left

💡 Hint

Common Mistakes

Using Depends(Query) which is invalid

Using Query(None) which makes the parameter optional

Use Query(...) to declare a required query parameter, and use Depends(get_query) to inject the dependency.

5fill in blank

hard

Fill all three blanks to create a dependency that reads a header and uses it in a path operation.

FastAPI

from fastapi import Header, Depends

async def get_user_agent(user_agent: str = [1]):
    return user_agent

@app.get("/info")
async def info(agent: str = [2]):
    return {"User-Agent": [3]

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

AHeader(None)

BDepends(get_user_agent)

Cagent

DHeader(...)

Attempts:

3 left

💡 Hint

Common Mistakes

Using Header(None) which makes the header optional

Returning the wrong variable name in the response

Use Header(...) to require the header, Depends(get_user_agent) to inject the dependency, and return the parameter agent in the response.