((1,2)) is not a singleton tuple containing another tuple for the same reason (1) is not a singleton tuple containing an int, because the outer parentheses don't make a tuple, the comma creates the tuple. you need ((1,2),) or even (1,2),
@MarkRansom it's the closest one, it's a common question of how to create a tuple with a single item, whether that item is an empty tuple or a 2 tuple doesn't seem that significant of a difference to me.
((1,2),).((1,2))is not a singleton tuple containing another tuple for the same reason(1)is not a singleton tuple containing anint, because the outer parentheses don't make a tuple, the comma creates the tuple. you need((1,2),)or even(1,2),