Update app.py

app.py

@@ -2,7 +2,7 @@ from flask import Flask, render_template, request, jsonify
 from werkzeug.utils import secure_filename
 import os
 from parser import parse_python_code
-
+from collections import defaultdict
 app = Flask(__name__)
 UPLOAD_FOLDER = 'uploads'
 app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER