Issue #16148: Small improvements and cleanup. Added version information

to docs.
This commit is contained in:
Armin Ronacher 2012-10-07 10:29:32 +02:00
parent 96e936712f
commit 74b38b190f
6 changed files with 24 additions and 9 deletions

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@ -349,6 +349,8 @@ is considered sufficient for this determination.
returning the default value. On error ``-1`` is returned. This is the
equivalent to the Python expression ``operator.length_hint(o, default)``.
.. versionadded:: 3.4
.. c:function:: PyObject* PyObject_GetItem(PyObject *o, PyObject *key)
Return element of *o* corresponding to the object *key* or *NULL* on failure.

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@ -241,6 +241,8 @@ their character equivalents.
actual length, then an estimate using ``__length_hint__``, and finally
returning the default value.
.. versionadded:: 3.4
The :mod:`operator` module also defines tools for generalized attribute and item
lookups. These are useful for making fast field extractors as arguments for
:func:`map`, :func:`sorted`, :meth:`itertools.groupby`, or other functions that

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@ -1805,6 +1805,15 @@ through the container; for mappings, :meth:`__iter__` should be the same as
considered to be false in a Boolean context.
.. method:: object.__length_hint__(self)
Called to implement ``operator.length_hint``. Should return an estimated
length for the object (which may be greater or less than the actual length).
The length must be an integer ``>=`` 0. This method is purely an
optimization and is never required for correctness.
.. versionadded:: 3.4
.. note::
Slicing is done exclusively with the following three methods. A call like ::

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@ -403,7 +403,9 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
PyAPI_FUNC(Py_ssize_t) PyObject_Length(PyObject *o);
#define PyObject_Length PyObject_Size
PyAPI_FUNC(int) _PyObject_HasLen(PyObject *o);
#ifndef Py_LIMITED_API
PyAPI_FUNC(int) _PyObject_HasLen(PyObject *o);
#endif
PyAPI_FUNC(Py_ssize_t) PyObject_LengthHint(PyObject *o, Py_ssize_t);
/*

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@ -170,7 +170,6 @@ class TestReversed(unittest.TestCase, PickleTest):
self.assertEqual(type(reversed(x)), type(iter(x)))
def test_len(self):
# This is an implementation detail, not an interface requirement
for s in ('hello', tuple('hello'), list('hello'), range(5)):
self.assertEqual(operator.length_hint(reversed(s)), len(s))
r = reversed(s)

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@ -71,8 +71,9 @@ _PyObject_HasLen(PyObject *o) {
}
/* The length hint function returns a non-negative value from o.__len__()
or o.__length_hint__(). If those methods aren't found. If one of the calls
fails this function returns -1.
or o.__length_hint__(). If those methods aren't found the defaultvalue is
returned. If one of the calls fails with an exception other than TypeError
this function returns -1.
*/
Py_ssize_t
@ -112,21 +113,21 @@ PyObject_LengthHint(PyObject *o, Py_ssize_t defaultvalue)
return defaultvalue;
}
if (!PyLong_Check(result)) {
PyErr_Format(PyExc_TypeError, "Length hint must be an integer, not %s",
PyErr_Format(PyExc_TypeError, "__length_hint__ must be an integer, not %.100s",
Py_TYPE(result)->tp_name);
Py_DECREF(result);
return -1;
}
defaultvalue = PyLong_AsSsize_t(result);
res = PyLong_AsSsize_t(result);
Py_DECREF(result);
if (defaultvalue < 0 && PyErr_Occurred()) {
if (res < 0 && PyErr_Occurred()) {
return -1;
}
if (defaultvalue < 0) {
if (res < 0) {
PyErr_Format(PyExc_ValueError, "__length_hint__() should return >= 0");
return -1;
}
return defaultvalue;
return res;
}
PyObject *