Can a KeyError occur in data structures other than standard dictionaries in Python?

KeyError is primarily associated with dictionary-like objects in Python. While it most commonly occurs with built-in `dict` instances, custom classes that implement the `__getitem__` method (to support bracket notation like `obj[key]`) can also raise a KeyError if they are designed to emulate dictionary behavior and a requested key is not found. It does not typically occur with sequences like lists or tuples, which raise an `IndexError` when an out-of-range integer index is used.