KeyError: 'height' - Ruff

What it does

Checks for subscript accesses with invalid keys and TypedDict construction with an unknown key.

Why is this bad?

Subscripting with an invalid key will raise a KeyError at runtime.

Creating a TypedDict with an unknown key is likely a mistake; if the TypedDict is closed=true it also violates the expectations of the type.

Examples

python

from typing import TypedDict
from typing_extensions import NotRequired


class Person(TypedDict):
    name: NotRequired[str]
    age: NotRequired[int]


alice = Person(name="Alice", age=30)
# KeyError: 'height'
alice["height"]  # error

# error
bob: Person = {"nickname": "Bob", "age": 30}  # typo!

# error
carol = Person(name="Carol", aeg=25)  # typo!