update app.py blogpost

services/blogpost/chall/app.py

@@ -1,7 +1,10 @@
 import os
 import sqlite3
-from flask import *
+from flask import (
-from werkzeug.utils import *
+    Flask, g, request, session, redirect, url_for,
+    render_template, render_template_string, flash, abort, send_from_directory
+)
+from werkzeug.utils import secure_filename
 from werkzeug.security import generate_password_hash, check_password_hash
 import hashlib
 import re