File responses in FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a file response in FastAPI?

A file response in FastAPI is a way to send files like images, PDFs, or any binary data back to the client as a response. It allows users to download or view files directly from the server.

beginner

Which FastAPI class is commonly used to send files as responses?

The <code>FileResponse</code> class from <code>fastapi.responses</code> is used to send files as responses. It handles setting the correct headers and streaming the file efficiently.

intermediate

How do you specify the filename for a file download in FastAPI?

You can specify the filename by using the filename parameter in FileResponse. This sets the name the user sees when downloading the file.

intermediate

What is the benefit of using FileResponse over reading and returning file bytes manually?

FileResponse streams the file efficiently without loading the entire file into memory. It also sets proper HTTP headers like Content-Type and Content-Disposition automatically.

intermediate

Can FileResponse be used to serve files stored outside the project directory?

Yes, as long as the file path is accessible by the server, FileResponse can serve files from any location on the server's file system.

Which FastAPI response class is designed to send files to clients?

A HTMLResponse

B JSONResponse

C FileResponse

D RedirectResponse

FileResponse is the class used to send files like images or documents to clients.

What parameter do you use in FileResponse to set the download filename?

A filename

B media_type

C content_type

D path

The filename parameter sets the name the user sees when downloading the file.

Why is FileResponse preferred over reading file bytes manually?

A It compresses files automatically

B It streams files efficiently and sets headers automatically

C It converts files to JSON

D It encrypts files before sending

FileResponse streams files without loading all bytes into memory and sets correct HTTP headers.

Can FileResponse serve files outside the FastAPI project folder?

A No, only files inside the project folder

B Only files uploaded by users

C Only files in a special static folder

D Yes, if the server has access to the file path

FileResponse can serve any file accessible by the server, regardless of location.

Which HTTP header does FileResponse set to suggest a file download?

A Content-Disposition

B Content-Length

C Content-Type

D Cache-Control

Content-Disposition header tells the browser to download the file with a given filename.

Explain how to send a file to a client using FastAPI and what benefits FileResponse provides.

Think about how to let users download or view files easily and efficiently.

Describe how you would serve a PDF file stored outside your FastAPI project folder to users.

Remember that file location on disk can be anywhere accessible by the server.