conn = sqlite3.connect(DATABASE)
c = conn.cursor()
-for vote in c.execute('select id, id_group, date_end, title from votes where is_open=1 and is_terminated=0'):
+for vote in c.execute('select id, id_group, date_end, title from votes where is_open=1 and is_terminated=0').fetchall():
date_end_vote = datetime.strptime(vote[2], "%Y-%m-%d")
date_today = datetime.today()
date_begin_reminder = date_end_vote + timedelta(days=-3)