Patch 1171 by mfenniak -- allow subclassing of bytes.

I suspect this has some problems when the subclass is evil,
but that's for later.
This commit is contained in:
Guido van Rossum 2007-11-03 00:24:24 +00:00
parent 2cc30daa86
commit a6c04bed1e
2 changed files with 92 additions and 6 deletions

View File

@ -3,6 +3,7 @@
import os
import re
import sys
import copy
import pickle
import tempfile
import unittest
@ -782,11 +783,89 @@ class BytesAsStringTest(test.string_tests.BaseTest):
pass
class BytesSubclass(bytes):
pass
class BytesSubclassTest(unittest.TestCase):
def test_basic(self):
self.assert_(issubclass(BytesSubclass, bytes))
self.assert_(isinstance(BytesSubclass(), bytes))
a, b = b"abcd", b"efgh"
_a, _b = BytesSubclass(a), BytesSubclass(b)
# test comparison operators with subclass instances
self.assert_(_a == _a)
self.assert_(_a != _b)
self.assert_(_a < _b)
self.assert_(_a <= _b)
self.assert_(_b >= _a)
self.assert_(_b > _a)
self.assert_(_a is not a)
# test concat of subclass instances
self.assertEqual(a + b, _a + _b)
self.assertEqual(a + b, a + _b)
self.assertEqual(a + b, _a + b)
# test repeat
self.assert_(a*5 == _a*5)
def test_join(self):
# Make sure join returns a NEW object for single item sequences
# involving a subclass.
# Make sure that it is of the appropriate type.
s1 = BytesSubclass(b"abcd")
s2 = b"".join([s1])
self.assert_(s1 is not s2)
self.assert_(type(s2) is bytes)
# Test reverse, calling join on subclass
s3 = s1.join([b"abcd"])
self.assert_(type(s3) is bytes)
def test_pickle(self):
a = BytesSubclass(b"abcd")
a.x = 10
a.y = BytesSubclass(b"efgh")
for proto in range(pickle.HIGHEST_PROTOCOL):
b = pickle.loads(pickle.dumps(a, proto))
self.assertNotEqual(id(a), id(b))
self.assertEqual(a, b)
self.assertEqual(a.x, b.x)
self.assertEqual(a.y, b.y)
self.assertEqual(type(a), type(b))
self.assertEqual(type(a.y), type(b.y))
def test_copy(self):
a = BytesSubclass(b"abcd")
a.x = 10
a.y = BytesSubclass(b"efgh")
for copy_method in (copy.copy, copy.deepcopy):
b = copy_method(a)
self.assertNotEqual(id(a), id(b))
self.assertEqual(a, b)
self.assertEqual(a.x, b.x)
self.assertEqual(a.y, b.y)
self.assertEqual(type(a), type(b))
self.assertEqual(type(a.y), type(b.y))
def test_init_override(self):
class subclass(bytes):
def __init__(self, newarg=1, *args, **kwargs):
bytes.__init__(self, *args, **kwargs)
x = subclass(4, source=b"abcd")
self.assertEqual(x, b"abcd")
x = subclass(newarg=4, source=b"abcd")
self.assertEqual(x, b"abcd")
def test_main():
test.test_support.run_unittest(BytesTest)
test.test_support.run_unittest(BytesAsStringTest)
test.test_support.run_unittest(BytesSubclassTest)
test.test_support.run_unittest(BufferPEP3137Test)
if __name__ == "__main__":
##test_main()
unittest.main()
test_main()

View File

@ -2921,13 +2921,21 @@ PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
static PyObject *
bytes_reduce(PyBytesObject *self)
{
PyObject *latin1;
PyObject *latin1, *dict;
if (self->ob_bytes)
latin1 = PyUnicode_DecodeLatin1(self->ob_bytes,
Py_Size(self), NULL);
else
latin1 = PyUnicode_FromString("");
return Py_BuildValue("(O(Ns))", Py_Type(self), latin1, "latin-1");
dict = PyObject_GetAttrString((PyObject *)self, "__dict__");
if (dict == NULL) {
PyErr_Clear();
dict = Py_None;
Py_INCREF(dict);
}
return Py_BuildValue("(O(Ns)N)", Py_Type(self), latin1, "latin-1", dict);
}
static PySequenceMethods bytes_as_sequence = {
@ -3045,8 +3053,7 @@ PyTypeObject PyBytes_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
&bytes_as_buffer, /* tp_as_buffer */
/* bytes is 'final' or 'sealed' */
Py_TPFLAGS_DEFAULT, /* tp_flags */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
bytes_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */