About the ex51 need help

I spend about two days to find and solve this problem. I tried some ways to do it ,but no one ways could finished .I need your helps.Thank you ever so much.

1 Like

Hello @W-JQ

If you add ”app.debug = True”
at the row above app.run() you will get more information about the reason for the error.
Also upload your code here.

This is my code.I thought that no any unlike… thanks…