Issue #13411: memoryview objects are now hashable when the underlying object is hashable.

2 files changed, 29 insertions, 2 deletions

diff --git a/Lib/test/test_memoryview.py b/Lib/test/test_memoryview.py
index 0bfddd9..a5a0ca1 100644
--- a/Lib/test/test_memoryview.py
+++ b/Lib/test/test_memoryview.py
@@ -283,6 +283,33 @@ class AbstractMemoryTests:
         i = io.BytesIO(b'ZZZZ')
         self.assertRaises(TypeError, i.readinto, m)
 
+    def test_hash(self):
+        # Memoryviews of readonly (hashable) types are hashable, and they
+        # hash as the corresponding object.
+        tp = self.ro_type
+        if tp is None:
+            self.skipTest("no read-only type to test")
+        b = tp(self._source)
+        m = self._view(b)
+        self.assertEqual(hash(m), hash(b"abcdef"))
+        # Releasing the memoryview keeps the stored hash value (as with weakrefs)
+        m.release()
+        self.assertEqual(hash(m), hash(b"abcdef"))
+        # Hashing a memoryview for the first time after it is released
+        # results in an error (as with weakrefs).
+        m = self._view(b)
+        m.release()
+        self.assertRaises(ValueError, hash, m)
+
+    def test_hash_writable(self):
+        # Memoryviews of writable types are unhashable
+        tp = self.rw_type
+        if tp is None:
+            self.skipTest("no writable type to test")
+        b = tp(self._source)
+        m = self._view(b)
+        self.assertRaises(ValueError, hash, m)
+
 # Variations on source objects for the buffer: bytes-like objects, then arrays
 # with itemsize > 1.
 # NOTE: support for multi-dimensional objects is unimplemented.
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index c99f4d7..ba0b592 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -770,8 +770,8 @@ class SizeofTest(unittest.TestCase):
         check(int(PyLong_BASE), size(vh) + 2*self.longdigit)
         check(int(PyLong_BASE**2-1), size(vh) + 2*self.longdigit)
         check(int(PyLong_BASE**2), size(vh) + 3*self.longdigit)
-        # memory
-        check(memoryview(b''), size(h + 'PP2P2i7P'))
+        # memory (Py_buffer + hash value)
+        check(memoryview(b''), size(h + 'PP2P2i7P' + 'P'))
         # module
         check(unittest, size(h + '3P'))
         # None