Python: How to define functions in loops using outer-scope variables?

Question

I want to define a function inside a loop using and changing variables which have been defined within the same loop iteration.

I would expect that nonlocal is just what i need here, but if i implement it like this

for i in range(5):
    obj = {"start": i}
    def update():
        nonlocal obj
        obj["next"] = obj["start"] + 1
        print(obj)
    update()

i get

  File "/path/to/test.py", line 4
    nonlocal obj
    ^^^^^^^^^^^^
SyntaxError: no binding for nonlocal 'obj' found

using Python 3.10.12 on Linux.