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gh-134114: Clarify FAQ note about dictonary keys (#134118)

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Stan Ulbrych 2025-05-18 16:59:20 +01:00 committed by GitHub
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@ -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?