Bug report

Bug description:

Negative/reverse slicing (_variable[_one:_two:-1]) is easy to misinterpret using only the two‑argument “indices between characters” model from the tutorial.

Example:

_variable = [1, 2, 3, 4]
print(_variable[2:0:-1])

Expected from two‑arg mental model: [2, 1]
Actual: [3, 2] — because:

• Stop index is always excluded, even when step is negative.
• Traversal starts at start and moves in step increments until it passes stop, never including stop.

The tutorial’s diagram is correct for step=1 but does not cover step at all, so readers extending that model to negative steps will predict the wrong result.

Proposed doc improvement: keep current explanation for two‑argument slices, but add a short note or link to the full slicing definition in the language reference showing how negative steps work, with a concrete example like [2:0:-1] → [3, 2]. This would prevent the confusion without overloading beginners.

CPython versions tested on:

3.15

Operating systems tested on:

No response