File validation (size, type) in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the FastAPI class.

FastAPI

from fastapi import [1]
app = [1]()

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AFastAPI

BFile

CRequest

DUploadFile

Attempts:

3 left

💡 Hint

Common Mistakes

Importing UploadFile instead of FastAPI

Using Request instead of FastAPI

The FastAPI class is imported to create the app instance.

2fill in blank

medium

Complete the code to accept a file upload in the endpoint.

FastAPI

@app.post('/upload')
async def upload_file(file: [1]):
    return {'filename': file.filename}

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Astr

BUploadFile

CFile

Dbytes

Attempts:

3 left

💡 Hint

Common Mistakes

Using str or bytes instead of UploadFile

Using File as a type instead of UploadFile

UploadFile is used to receive uploaded files in FastAPI endpoints.

3fill in blank

hard

Fix the error in the code to limit file size to 1MB.

FastAPI

from fastapi import File, UploadFile

@app.post('/upload')
async def upload_file(file: UploadFile = File(..., [1]=1048576)):
    return {'filename': file.filename}

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Amax_file_size

Bmax_length

Cmax_size

Dmax_bytes

Attempts:

3 left

💡 Hint

Common Mistakes

Using max_length or max_file_size which are invalid

Using max_bytes which is not recognized

The correct parameter to limit file size in File() is max_size.

4fill in blank

hard

Fill both blanks to check the uploaded file's content type and reject if not an image.

FastAPI

from fastapi import HTTPException

@app.post('/upload')
async def upload_file(file: UploadFile):
    if file.content_type != [1]:
        raise HTTPException(status_code=400, detail=[2])
    return {'filename': file.filename}

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A'image/png'

B'Invalid file type'

C'application/pdf'

D'File type not allowed'

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for wrong content type like 'application/pdf'

Using incorrect error messages

We check if the file's content_type is 'image/png' and raise an error with message 'Invalid file type' if not.

5fill in blank

hard

Fill all three blanks to create a file validation that accepts only JPEG images under 2MB.

FastAPI

from fastapi import File, UploadFile, HTTPException

@app.post('/upload')
async def upload_file(file: UploadFile = File(..., [1]=2097152)):
    if file.content_type != [2]:
        raise HTTPException(status_code=400, detail=[3])
    return {'filename': file.filename}

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

Amax_size

B'image/jpeg'

C'Only JPEG images under 2MB are allowed'

D'image/png'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong max_size parameter

Checking for 'image/png' instead of 'image/jpeg'

Incorrect error messages

max_size limits file size to 2MB, content_type is checked for 'image/jpeg', and error message explains the restriction.