Flask logout if sessions expires if no activity and redirect for login page
<p>I'm very new to flask and trying updating a website with flask where users have accounts and are able to login. I want to make user session expire and logout if there is no activity for more than 10 mins and redirect the user for login page.</p>

<p>I want to update it in @app.before_request  and below is my code . How do i update it pls suggest.
Check for the login time and check if there is been no activity then logout.</p>

<pre><code>@app.before_request
def look_for_user(user=None):
        g.usr = {}
    g.api = False
    if user:
        g.usr = user
    if 'user_id' in session:
        g.usr = get_user((session['user_id'])) //from db
        if not g.usr:
            g.usr = {}
    if not g.usr:
        if request.url_rule:
            if request.url_rule.rule not in app.config['LOGIN_NOT_REQUIRED']:
                session['postlogin_landing_page'] = request.path
                if g.api:
                    return jsonify(error=True, error_message='Invalid Login/Token')
                else:
                    return redirect(app.config['LOGIN_URL'])
    elif 'login_page' in session and request.url_rule:
        if request.url_rule.rule not in app.config:
            landing_page = session.pop('login_page')
            return redirect(landing_page)
</code></pre>

<p>You can use <code>permanent_session_lifetime</code> and the <code>session.modified</code> flag as described in <a href="http://stackoverflow.com/questions/19760486/resetting-the-expiration-time-for-a-cookie-in-flask/19795394">this question</a>.</p>

<p>Note that sessions are not permanent by default, and need to be activated with <code>session.permanent = True</code>, as described in <a href="http://stackoverflow.com/a/11785722/246534">this answer</a>.</p>

python redirect flask logout expired-sessions