Update app.py

app.py

@@ -13,8 +13,9 @@ from codeinterpreterapi import CodeInterpreterSession
 def codeinterpreter(openai_key,prompt, files):
 
     fileList = []
-    for idx, file in enumerate(files):
-        fileList.append(file)
+    if files != None:
+        for idx, file in enumerate(files):
+            fileList.append(file)
 
     with CodeInterpreterSession(model="gpt-3.5",openai_api_key=openai_key) as session:
     #async with CodeInterpreterSession(model="gpt-3.5-turbo",openai_api_key="") as session: