bpo-32492: Tweak _collections._tuplegetter. (GH-11367)

* Replace the docstrings cache with sys.intern().
* Improve tests.
* Unify names of tp_descr_get and tp_descr_set functions.
This commit is contained in:
Serhiy Storchaka 2018-12-31 14:15:16 +02:00 committed by GitHub
parent 5c117dd227
commit 052b2dfdc9
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4 changed files with 75 additions and 37 deletions

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@ -316,8 +316,6 @@ try:
except ImportError:
_tuplegetter = lambda index, doc: property(_itemgetter(index), doc=doc)
_nt_itemgetters = {}
def namedtuple(typename, field_names, *, rename=False, defaults=None, module=None):
"""Returns a new subclass of tuple with named fields.
@ -456,16 +454,9 @@ def namedtuple(typename, field_names, *, rename=False, defaults=None, module=Non
'_asdict': _asdict,
'__getnewargs__': __getnewargs__,
}
cache = _nt_itemgetters
for index, name in enumerate(field_names):
try:
doc = cache[index]
except KeyError:
doc = f'Alias for field number {index}'
cache[index] = doc
tuplegetter_object = _tuplegetter(index, doc)
class_namespace[name] = tuplegetter_object
doc = _sys.intern(f'Alias for field number {index}')
class_namespace[name] = _tuplegetter(index, doc)
result = type(typename, (tuple,), class_namespace)

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@ -3,6 +3,7 @@
import collections
import copy
import doctest
import inspect
import operator
import pickle
from random import choice, randrange
@ -281,20 +282,50 @@ class TestNamedTuple(unittest.TestCase):
self.assertEqual(Point(1), (1, 20))
self.assertEqual(Point(), (10, 20))
def test_readonly(self):
Point = namedtuple('Point', 'x y')
p = Point(11, 22)
with self.assertRaises(AttributeError):
p.x = 33
with self.assertRaises(AttributeError):
del p.x
with self.assertRaises(TypeError):
p[0] = 33
with self.assertRaises(TypeError):
del p[0]
self.assertEqual(p.x, 11)
self.assertEqual(p[0], 11)
@unittest.skipIf(sys.flags.optimize >= 2,
"Docstrings are omitted with -O2 and above")
def test_factory_doc_attr(self):
Point = namedtuple('Point', 'x y')
self.assertEqual(Point.__doc__, 'Point(x, y)')
Point.__doc__ = '2D point'
self.assertEqual(Point.__doc__, '2D point')
@unittest.skipIf(sys.flags.optimize >= 2,
"Docstrings are omitted with -O2 and above")
def test_doc_writable(self):
def test_field_doc(self):
Point = namedtuple('Point', 'x y')
self.assertEqual(Point.x.__doc__, 'Alias for field number 0')
self.assertEqual(Point.y.__doc__, 'Alias for field number 1')
Point.x.__doc__ = 'docstring for Point.x'
self.assertEqual(Point.x.__doc__, 'docstring for Point.x')
# namedtuple can mutate doc of descriptors independently
Vector = namedtuple('Vector', 'x y')
self.assertEqual(Vector.x.__doc__, 'Alias for field number 0')
Vector.x.__doc__ = 'docstring for Vector.x'
self.assertEqual(Vector.x.__doc__, 'docstring for Vector.x')
@support.cpython_only
@unittest.skipIf(sys.flags.optimize >= 2,
"Docstrings are omitted with -O2 and above")
def test_field_doc_reuse(self):
P = namedtuple('P', ['m', 'n'])
Q = namedtuple('Q', ['o', 'p'])
self.assertIs(P.m.__doc__, Q.o.__doc__)
self.assertIs(P.n.__doc__, Q.p.__doc__)
def test_name_fixer(self):
for spec, renamed in [
@ -319,16 +350,18 @@ class TestNamedTuple(unittest.TestCase):
self.assertEqual(p, Point(y=22, x=11))
self.assertEqual(p, Point(*(11, 22)))
self.assertEqual(p, Point(**dict(x=11, y=22)))
self.assertRaises(TypeError, Point, 1) # too few args
self.assertRaises(TypeError, Point, 1, 2, 3) # too many args
self.assertRaises(TypeError, eval, 'Point(XXX=1, y=2)', locals()) # wrong keyword argument
self.assertRaises(TypeError, eval, 'Point(x=1)', locals()) # missing keyword argument
self.assertRaises(TypeError, Point, 1) # too few args
self.assertRaises(TypeError, Point, 1, 2, 3) # too many args
with self.assertRaises(TypeError): # wrong keyword argument
Point(XXX=1, y=2)
with self.assertRaises(TypeError): # missing keyword argument
Point(x=1)
self.assertEqual(repr(p), 'Point(x=11, y=22)')
self.assertNotIn('__weakref__', dir(p))
self.assertEqual(p, Point._make([11, 22])) # test _make classmethod
self.assertEqual(p._fields, ('x', 'y')) # test _fields attribute
self.assertEqual(p._replace(x=1), (1, 22)) # test _replace method
self.assertEqual(p._asdict(), dict(x=11, y=22)) # test _asdict method
self.assertEqual(p, Point._make([11, 22])) # test _make classmethod
self.assertEqual(p._fields, ('x', 'y')) # test _fields attribute
self.assertEqual(p._replace(x=1), (1, 22)) # test _replace method
self.assertEqual(p._asdict(), dict(x=11, y=22)) # test _asdict method
try:
p._replace(x=1, error=2)
@ -360,11 +393,15 @@ class TestNamedTuple(unittest.TestCase):
x, y = p
self.assertEqual(p, (x, y)) # unpacks like a tuple
self.assertEqual((p[0], p[1]), (11, 22)) # indexable like a tuple
self.assertRaises(IndexError, p.__getitem__, 3)
with self.assertRaises(IndexError):
p[3]
self.assertEqual(p[-1], 22)
self.assertEqual(hash(p), hash((11, 22)))
self.assertEqual(p.x, x)
self.assertEqual(p.y, y)
self.assertRaises(AttributeError, eval, 'p.z', locals())
with self.assertRaises(AttributeError):
p.z
def test_odd_sizes(self):
Zero = namedtuple('Zero', '')
@ -514,13 +551,13 @@ class TestNamedTuple(unittest.TestCase):
a.w = 5
self.assertEqual(a.__dict__, {'w': 5})
def test_namedtuple_can_mutate_doc_of_descriptors_independently(self):
A = namedtuple('A', 'x y')
B = namedtuple('B', 'x y')
A.x.__doc__ = 'foo'
B.x.__doc__ = 'bar'
self.assertEqual(A.x.__doc__, 'foo')
self.assertEqual(B.x.__doc__, 'bar')
def test_field_descriptor(self):
Point = namedtuple('Point', 'x y')
p = Point(11, 22)
self.assertTrue(inspect.isdatadescriptor(Point.x))
self.assertEqual(Point.x.__get__(p), 11)
self.assertRaises(AttributeError, Point.x.__set__, p, 33)
self.assertRaises(AttributeError, Point.x.__delete__, p)
################################################################################

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@ -687,6 +687,16 @@ class PydocDocTest(unittest.TestCase):
finally:
pydoc.getpager = getpager_old
def test_namedtuple_fields(self):
Person = namedtuple('Person', ['nickname', 'firstname'])
with captured_stdout() as help_io:
pydoc.help(Person)
helptext = help_io.getvalue()
self.assertIn("nickname", helptext)
self.assertIn("firstname", helptext)
self.assertIn("Alias for field number 0", helptext)
self.assertIn("Alias for field number 1", helptext)
def test_namedtuple_public_underscore(self):
NT = namedtuple('NT', ['abc', 'def'], rename=True)
with captured_stdout() as help_io:

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@ -2336,7 +2336,7 @@ done:
Py_RETURN_NONE;
}
/* Helper functions for namedtuples */
/* Helper function for namedtuple() ************************************/
typedef struct {
PyObject_HEAD
@ -2369,9 +2369,11 @@ tuplegetter_new_impl(PyTypeObject *type, Py_ssize_t index, PyObject *doc)
}
static PyObject *
tuplegetterdescr_get(PyObject *self, PyObject *obj, PyObject *type)
tuplegetter_descr_get(PyObject *self, PyObject *obj, PyObject *type)
{
Py_ssize_t index = ((_tuplegetterobject*)self)->index;
PyObject *result;
if (obj == NULL) {
Py_INCREF(self);
return self;
@ -2384,13 +2386,11 @@ tuplegetterdescr_get(PyObject *self, PyObject *obj, PyObject *type)
PyErr_Format(PyExc_TypeError,
"descriptor for index '%d' for tuple subclasses "
"doesn't apply to '%s' object",
((_tuplegetterobject*)self)->index,
index,
obj->ob_type->tp_name);
return NULL;
}
Py_ssize_t index = ((_tuplegetterobject*)self)->index;
if (!valid_index(index, PyTuple_GET_SIZE(obj))) {
PyErr_SetString(PyExc_IndexError, "tuple index out of range");
return NULL;
@ -2402,7 +2402,7 @@ tuplegetterdescr_get(PyObject *self, PyObject *obj, PyObject *type)
}
static int
tuplegetter_set(PyObject *self, PyObject *obj, PyObject *value)
tuplegetter_descr_set(PyObject *self, PyObject *obj, PyObject *value)
{
if (value == NULL) {
PyErr_SetString(PyExc_AttributeError, "can't delete attribute");
@ -2476,8 +2476,8 @@ static PyTypeObject tuplegetter_type = {
0, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
tuplegetterdescr_get, /* tp_descr_get */
tuplegetter_set, /* tp_descr_set */
tuplegetter_descr_get, /* tp_descr_get */
tuplegetter_descr_set, /* tp_descr_set */
0, /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */