tuples_index error

Tuple index out of bounds

When a fixed-length tupleT1, T2, ... variable is indexed with a literal integer or a LiteralN-typed variable that is outside the valid range [-len, len), this is a static error.

v: tuple[int, str, list[bool]] = (3, "hi", [True])
v[4]   # E0103 — index 4 out of range for 3-element tuple
v[-4]  # E0103 — index -4 out of range for 3-element tuple

How to handle it

Every rule is on by default — strict is the default, not a cage. You can dial tuples_index down per-file or per-path from your editor or pyproject.toml, or fix the code so it type-checks. See the Type System rules and the complete diagnostic reference.

Canonical URL: https://www.basilisk-python.dev/errors/tuples_index