"1,+2,", but not "(1,)+2,"

[Jon Ribbens]

On 2020-07-31, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>   You can write
>
>|>>> 1,+2,
>|(1, 2)
>
>   , but not
>
>|>>> (1,)+2,
>|TypeError: can only concatenate tuple (not "int") to tuple
>
>   . Why? (Python 3.9)

For the obvious reason, as indicated by the error message?

What are you expecting these expressions to mean?