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| -rw-r--r-- | Doc/glossary.rst | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Doc/glossary.rst b/Doc/glossary.rst index d3ce365..177df54 100644 --- a/Doc/glossary.rst +++ b/Doc/glossary.rst @@ -512,8 +512,10 @@ Glossary Hashability makes an object usable as a dictionary key and a set member, because these data structures use the hash value internally. - All of Python's immutable built-in objects are hashable; mutable - containers (such as lists or dictionaries) are not. Objects which are + Most of Python's immutable built-in objects are hashable; mutable + containers (such as lists or dictionaries) are not; immutable + containers (such as tuples and frozensets) are only hashable if + their elements are hashable. Objects which are instances of user-defined classes are hashable by default. They all compare unequal (except with themselves), and their hash value is derived from their :func:`id`. |