Updating dictionary with tuple

[Gribouillis]

Here is the documentation of dict.update

Output:
D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.
    If E is present and has a .keys() method, then does:  for k in E: D[k] = E[k]
    If E is present and lacks a .keys() method, then does:  for k, v in E: D[k] = v
    In either case, this is followed by: for k in F:  D[k] = F[k]

In your case, E = (2, 9) so we are in a case of a sequence that lacks a .keys() method, and the function expects a sequence of pairs, not a sequence of integers.
You could use [(2, 9)] instead of (2, 9)