Solved by mrshenli in post #5 
              
              
                Could you explain why it is? 

Sure. If you don’t add a comma, Python would not recognize it as a tuple. See the following code: 
Python 3.8.2 (default, Mar 26 2020, 15:53:00)
[GCC 7.3.0] :: Anaconda, Inc. on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> (5) == 5
…