openpyxl.errors

Typed exceptions for paper-xlsx safety refusals.

Every preserve-mode operation completes correctly or refuses with a PaperRefusal subclass saying what was found and why it was unsafe. Writes to protected cells can also emit an explicit advisory warning. A refused operation leaves the in-memory model, dirty ledger, and destination exactly as they were.

Programmer errors (invalid argument combinations, wrong types) remain TypeError/ValueError and are deliberately NOT part of this hierarchy.