Python Flask - how to remember anonymous users via cookie/session?
There is no perfect solution to your problem because you will not be able to identify a user if they are anonymous.
The most practical is probably to use sessions and save that they completed the survey in a session variable. But if they clear their cookies they will be able to enter the site again.
Example implementation:
from flask import session, app@app.before_requestdef make_session_permanent(): session.permanent = TrueIn your survey form view:
if not "already_participated" in session: ... Display formAnd then in your submit view:
session["already_participated"] = True