How to replace whitespace contained in strings represented by keywords?

[Miroslav-Cetojevic]

Example from gallery-dl.conf:

"filename": "{title.replace(\" \",\"_\")}-by-{userinfo[username]}-{asset[id]}.{extension}"

It doesn't work as the result is simply None, so the filenames all get prefixed with None. Is there another way?

[mikf]

{title:R /_/}, or in general with the path-restrict option. ("\\\\|/<>:\"?* " when you're on Windows)

[Miroslav-Cetojevic]

Turns out, the "ascii" option of path-restrict does what I need. Thanks for pointing this particular conf option out.