ram at zedat.fu-berlin.de (Stefan Ram): > Steve D'Aprano <steve+python at pearwood.info> writes: >>There's a word for frozen list: "tuple". >> Yes, but one should not forget that a tuple > can contain mutable entries (such as lists). Not when used as keys: >>> hash(([], [])) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unhashable type: 'list' Marko