Flask/Werkzeug how to attach HTTP content-length header to file download

Question

Hi,

I am using Flask (based on Werkzeug) which uses Python.

So the user can download a file, I'm using the send_from_directory function: http://flask.pocoo.org/docs/api/?highlight=send_from_directory#flask.send_from_directory

However when actually downloading the file, the HTTP header content-length is not set. So the user has no idea how big the file being downloaded is.

I can use os.path.getsize(FILE_LOCATION) in Python to get the file size (in bytes), but cannot find a way to set the content-length header in Flask.

Any ideas?

Answer 1

I believe you'd do something like this (untested):

from flask import Response
Response.headers.add('content-length', str(os.path.getsize(FILE_LOCATION)))

See: Werkzug's Headers object and Flask's Response object.