[Python-3000-checkins] r59104 - in python/branches/py3k/Lib: _abcoll.py test/test_collections.py

[guido.van.rossum]

Author: guido.van.rossum
Date: Wed Nov 21 23:26:24 2007
New Revision: 59104

Modified:
   python/branches/py3k/Lib/_abcoll.py
   python/branches/py3k/Lib/test/test_collections.py
Log:
Add ABC ByteString which unifies bytes and bytearray (but not memoryview).
There's no ABC for "PEP 3118 style buffer API objects" because there's no
way to recognize these in Python (apart from trying to use memoryview()
on them).
Note that array.array really should be registered as a MutableSequence
but that would require importing it whenever collections is imported.


Modified: python/branches/py3k/Lib/_abcoll.py
==============================================================================
--- python/branches/py3k/Lib/_abcoll.py	(original)
+++ python/branches/py3k/Lib/_abcoll.py	Wed Nov 21 23:26:24 2007
@@ -16,6 +16,7 @@
            "Mapping", "MutableMapping",
            "MappingView", "KeysView", "ItemsView", "ValuesView",
            "Sequence", "MutableSequence",
+           "ByteString",
            ]
 
 ### ONE-TRICK PONIES ###
@@ -489,8 +490,17 @@
 
 Sequence.register(tuple)
 Sequence.register(str)
-Sequence.register(bytes)
-Sequence.register(memoryview)
+
+
+class ByteString(Sequence):
+
+    """This unifies bytes and bytearray.
+
+    XXX Should add all their methods.
+    """
+
+ByteString.register(bytes)
+ByteString.register(bytearray)
 
 
 class MutableSequence(Sequence):
@@ -531,4 +541,4 @@
         self.extend(values)
 
 MutableSequence.register(list)
-MutableSequence.register(bytes)
+MutableSequence.register(bytearray)  # Multiply inheriting, see ByteString

Modified: python/branches/py3k/Lib/test/test_collections.py
==============================================================================
--- python/branches/py3k/Lib/test/test_collections.py	(original)
+++ python/branches/py3k/Lib/test/test_collections.py	Wed Nov 21 23:26:24 2007
@@ -8,6 +8,7 @@
 from collections import Set, MutableSet
 from collections import Mapping, MutableMapping
 from collections import Sequence, MutableSequence
+from collections import ByteString
 
 
 class TestNamedTuple(unittest.TestCase):
@@ -260,11 +261,21 @@
             self.failUnless(issubclass(sample, Sequence))
         self.failUnless(issubclass(str, Sequence))
 
+    def test_ByteString(self):
+        for sample in [bytes, bytearray]:
+            self.failUnless(isinstance(sample(), ByteString))
+            self.failUnless(issubclass(sample, ByteString))
+        for sample in [str, list, tuple]:
+            self.failIf(isinstance(sample(), ByteString))
+            self.failIf(issubclass(sample, ByteString))
+        self.failIf(isinstance(memoryview(b""), ByteString))
+        self.failIf(issubclass(memoryview, ByteString))
+
     def test_MutableSequence(self):
-        for sample in [tuple, str]:
+        for sample in [tuple, str, bytes]:
             self.failIf(isinstance(sample(), MutableSequence))
             self.failIf(issubclass(sample, MutableSequence))
-        for sample in [list, bytes]:
+        for sample in [list, bytearray]:
             self.failUnless(isinstance(sample(), MutableSequence))
             self.failUnless(issubclass(sample, MutableSequence))
         self.failIf(issubclass(str, MutableSequence))