https://github.com/python/cpython/commit/b1c33294ca5ef8d889f2ec87f9a8fa79741f9f7d commit: b1c33294ca5ef8d889f2ec87f9a8fa79741f9f7d branch: main author: Stan Ulbrych <89152624+stanfromirel...@users.noreply.github.com> committer: kumaraditya303 <kumaradi...@python.org> date: 2025-05-18T15:59:20Z summary:
gh-134114: Clarify FAQ note about dictonary keys (#134118) files: M Doc/faq/design.rst diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst index e2710fab9cf800..c758c019ca437b 100644 --- a/Doc/faq/design.rst +++ b/Doc/faq/design.rst @@ -420,10 +420,12 @@ strings representing the files in the current directory. Functions which operate on this output would generally not break if you added another file or two to the directory. -Tuples are immutable, meaning that once a tuple has been created, you can't -replace any of its elements with a new value. Lists are mutable, meaning that -you can always change a list's elements. Only immutable elements can be used as -dictionary keys, and hence only tuples and not lists can be used as keys. +Tuples are :term:`immutable`, meaning that once a tuple has been created, you can't +replace any of its elements with a new value. Lists are :term:`mutable`, meaning that +you can always change a list's elements. Only :term:`hashable` objects can +be used as dictionary keys. Most immutable types are hashable, which is why +tuples, but not lists, can be used as keys. Note, however, that a tuple is +only hashable if all of its elements are hashable. How are lists implemented in CPython? _______________________________________________ Python-checkins mailing list -- python-checkins@python.org To unsubscribe send an email to python-checkins-le...@python.org https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: arch...@mail-archive.com
