First, please avoid sharing your code as it is against the community code of conduct.
Simply run all the above cells or do Kernel → Restart & Run All.
So sorry to do so sir, but I have been doing the methods u said for a long time, still I could not find any success.
Then maybe you have deleted/modified some code or cells. Please see this guide to get a clean copy of your assignment and do your code again, without deleting/modifying any other code/cells.
Thank you so much sir. I am sorry to have violated the rules. Have a good night!