Multiple file uploads in FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of using List[UploadFile] in FastAPI?

It allows the API endpoint to accept multiple files uploaded at once by the client, handling each file as an UploadFile object.

beginner

How do you declare a FastAPI endpoint to accept multiple files?

Use a parameter with type List[UploadFile] and add File(...) to tell FastAPI to expect multiple files in the request.

intermediate

What is the difference between UploadFile and bytes in FastAPI file uploads?

UploadFile provides a file-like interface with metadata and async methods, while bytes reads the entire file content into memory as raw bytes.

intermediate

Why is it better to use UploadFile for multiple file uploads instead of reading files as bytes?

Because UploadFile streams files efficiently without loading everything into memory, which is important when handling many or large files.

beginner

How can you access the filename of each uploaded file in FastAPI?

Each UploadFile object has a filename attribute that contains the original name of the uploaded file.

Which type hint allows a FastAPI endpoint to accept multiple uploaded files?

A UploadFile

B List[UploadFile]

C bytes

D str

Using List[UploadFile] tells FastAPI to expect multiple files uploaded as a list.

What decorator parameter is used to mark a parameter as a file upload in FastAPI?

A Query(...)

B Body(...)

C File(...)

D Path(...)

File(...) marks the parameter as a file upload.

What attribute of UploadFile gives you the original filename?

A filename

B file_name

C name

D title

The filename attribute contains the original file name.

Why is UploadFile preferred over bytes for large files?

A It streams the file efficiently without loading all at once

B It compresses files

C It converts files to text automatically

D It loads the entire file into memory

UploadFile streams files efficiently, saving memory.

How do you declare a FastAPI endpoint parameter to accept multiple files?

A files: UploadFile = File(...)

B files: bytes = File(...)

C files: str = File(...)

D files: List[UploadFile] = File(...)

Use List[UploadFile] with File(...) to accept multiple files.

Explain how to create a FastAPI endpoint that accepts multiple file uploads and processes each file.

Think about how to receive and loop through files in the endpoint function.

Describe the advantages of using UploadFile over bytes when handling multiple file uploads in FastAPI.

Consider memory usage and file handling features.