[Python-checkins] bpo-42345: Fix hash implementation of typing.Literal (GH-23383)

Thu Nov 19 11:17:47 EST 2020

https://github.com/python/cpython/commit/1b54077ff6f5c1379e097e9f8e8648da9826d6ec
commit: 1b54077ff6f5c1379e097e9f8e8648da9826d6ec
branch: master
author: Yurii Karabas <1998uriyyo at gmail.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2020年11月19日T08:17:38-08:00
summary:
bpo-42345: Fix hash implementation of typing.Literal (GH-23383)
Fix hash implementation of `typing.Literal`.
Update docs regarding `typing.Litaral` caching.
Base implementation was done in PR #23294.
files:
M Doc/library/typing.rst
M Lib/test/test_typing.py
M Lib/typing.py

diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst
index a8de984a5ce41..5b66e3c2c5b63 100644
--- a/Doc/library/typing.rst
+++ b/Doc/library/typing.rst
@@ -1706,9 +1706,9 @@ Introspection helpers
 For a typing object of the form ``X[Y, Z, ...]`` these functions return
 ``X`` and ``(Y, Z, ...)``. If ``X`` is a generic alias for a builtin or
 :mod:`collections` class, it gets normalized to the original class.
- If ``X`` is a :class:`Union` contained in another generic type,
- the order of ``(Y, Z, ...)`` may be different from the order of
- the original arguments ``[Y, Z, ...]`` due to type caching.
+ If ``X`` is a :class:`Union` or :class:`Literal` contained in another
+ generic type, the order of ``(Y, Z, ...)`` may be different from the order
+ of the original arguments ``[Y, Z, ...]`` due to type caching.
 For unsupported objects return ``None`` and ``()`` correspondingly.
 Examples::
 
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 7deba0d71b7c4..8ffc7f40cebdd 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -569,6 +569,11 @@ def test_equal(self):
 self.assertEqual(Literal[1, 2], Literal[2, 1])
 self.assertEqual(Literal[1, 2, 3], Literal[1, 2, 3, 3])
 
+ def test_hash(self):
+ self.assertEqual(hash(Literal[1]), hash(Literal[1]))
+ self.assertEqual(hash(Literal[1, 2]), hash(Literal[2, 1]))
+ self.assertEqual(hash(Literal[1, 2, 3]), hash(Literal[1, 2, 3, 3]))
+
 def test_args(self):
 self.assertEqual(Literal[1, 2, 3].__args__, (1, 2, 3))
 self.assertEqual(Literal[1, 2, 3, 3].__args__, (1, 2, 3))
diff --git a/Lib/typing.py b/Lib/typing.py
index d310b3dd5820d..46c54c406992f 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -981,7 +981,7 @@ def __eq__(self, other):
 return set(_value_and_type_iter(self.__args__)) == set(_value_and_type_iter(other.__args__))
 
 def __hash__(self):
- return hash(tuple(_value_and_type_iter(self.__args__)))
+ return hash(frozenset(_value_and_type_iter(self.__args__)))
 
 
 class Generic:
