Flask - handling unicode text with werkzeug?

Question

So I am trying to have a browser download a file with a certain name, which is stored in a database. To prevent filename conflicts the file is saved on disk with a GUID, and when it comes time to actually download it, the filename from the database is supplied for the browser. The name is written in Japanese, and when I display it on the page it comes out fine, so it is stored OK in the database. When I try to actually have the browser download it under that name: ``` return send_from_directory(app.config['FILE_FOLDER'], name_on_disk, as_attachment=True, attachment_filename = filename) ``` Flask throws an error: ``` UnicodeEncodeError: 'ascii' codec can't encode characters in position 15-20: ordinal not in range(128) ``` The error seems to originate not from my code, but from part of Werkzeug: ``` /werkzeug/http.py", line 150, in quote_header_value value = str(value) ``` Why is this happening? According to their docs, Flask is "100% Unicode" I actually had this problem before I rewrot…

Accepted Answer

You should explictly pass unicode strings (type `unicode`) when dealing with non-ASCII data. Generally in Flask, bytestrings are assumed to have an `ascii` encoding.

Flask - handling unicode text with werkzeug?

Solution

Problem