marimo dev here.

Just wanted to mention that you're always able to do this:

for _x in range(100): ...

This way, `_x` is detected as a throwaway Python variable. And it won't re-appear in other cells.

Also, within the same cell you can always re-assign. But you can't do that in another cell. We want to ensure that a variable is fully declared in one, and only one, cell.

``` # cell A, totally fine

a = 1 for _ in range(100): a = a + 1

# but don't re-assign a in another cell. ```