On Mon, 2026-01-19 at 17:45 -0300, Wander Lairson Costa wrote:

Initialize loop variable `i` before the for loop in abbreviate_atoms
function to fix pyright static type checker error. The previous code
left `i` potentially unbound in edge cases where the range could be
empty, though this would not occur in practice since the loop always
executes at least once with the given range parameters.

The initialization to zero ensures that `i` has a defined value before
entering the loop scope, satisfying static analysis requirements
while preserving the existing logic. The for loop immediately assigns
i to the first value from the range, so the initialization value is
never actually used in normal execution paths.

This change resolves the pyright reportPossiblyUnbound error without
altering the function's behavior or performance characteristics.

So are we just pleasing the tool or is there a real implication of this?

Apparently code like

for i in range(len([]), -1, -1):
    pass
print(i)

works just fine since range() returns at least 0 (as you mentioned in the commit
message) and i is not used before assignation in the loop, so I don't really see
a problem.

Apparently pyright devs don't want ([1]) to implement a logic to sort out the
/possibly/ unbound error here.

From what I understand, this code is already not pythonic, so rather than
silence the warning to please this tool I'd just refactor the code not to use i
after the loop (or leave it as it is, since it works fine).

What do you think?

Thanks,
Gabriele

[1] - https://github.com/microsoft/pyright/issues/844