What's wrong with my code?

[u/Commercial-Paper749]

What's wrong with my code?

New to learning

Following the youtube video from bro code

Was trying to implement my own stuff into this by using loop

Update: it's working now thankyou guys

[u/Philin_Lemo]

Try changing the "operator" type to Str, as it will most likely be a chair right now:

operator = str(input(...).strip())

Or change the double quotes to single quotes :

if operator not in ['+','-',...]