Consider using a While loop. Specifically, just inserting all your code as follows should do the job:
**While True:**
.....
.....
I have not run your code, but I think a break statement would be needed for your final “if” statement (in order to not run endlessly), specifically:
if op.lower() in {'q', 'quit', 'e', 'exit'}:
print("Goodbye!")
break
Apart from those edits, I think that all the inputting and whatnot should be fine.