namedtuples_type_compat error

NamedTuple-to-tuple type incompatibility

When a NamedTuple instance is assigned to a variable annotated with a fixed-length tuple... type, Basilisk verifies:

1. The element count matches the number of fields in the NamedTuple. 2. Each element type in the tuple annotation is compatible with the corresponding NamedTuple field type (with covariance).

class Point(NamedTuple):
    x: int
    y: int
    units: str = "meters"

p = Point(x=1, y=2, units="inches")
v1: tuple[int, int, str] = p  # OK
v2: tuple[int, int] = p       # E -- too few elements (2 vs 3 fields)
v3: tuple[int, str, str] = p  # E -- incompatible element type

How to handle it

Every rule is on by default — strict is the default, not a cage. You can dial namedtuples_type_compat 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/namedtuples_type_compat