diff options
| -rw-r--r-- | Doc/library/collections.rst | 6 | ||||
| -rw-r--r-- | Lib/test/test_deque.py | 24 | ||||
| -rw-r--r-- | Misc/NEWS | 2 | ||||
| -rw-r--r-- | Modules/_collectionsmodule.c | 42 |
4 files changed, 73 insertions, 1 deletions
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst index aa17a55..3d04063 100644 --- a/Doc/library/collections.rst +++ b/Doc/library/collections.rst @@ -338,6 +338,12 @@ counts, but the output will exclude results with counts of zero or less. Remove all elements from the deque leaving it with length 0. + .. method:: count(x) + + Count the number of deque elements equal to *x*. + + .. versionadded:: 3.2 + .. method:: extend(iterable) Extend the right side of the deque by appending elements from the iterable diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py index a2f5fae..17d724c 100644 --- a/Lib/test/test_deque.py +++ b/Lib/test/test_deque.py @@ -114,6 +114,30 @@ class TestBasic(unittest.TestCase): d = deque('abc') d.maxlen = 10 + def test_count(self): + for s in ('', 'abracadabra', 'simsalabim'*500+'abc'): + s = list(s) + d = deque(s) + for letter in 'abcdefghijklmnopqrstuvwxyz': + self.assertEqual(s.count(letter), d.count(letter), (s, d, letter)) + self.assertRaises(TypeError, d.count) # too few args + self.assertRaises(TypeError, d.count, 1, 2) # too many args + class BadCompare: + def __eq__(self, other): + raise ArithmeticError + d = deque([1, 2, BadCompare(), 3]) + self.assertRaises(ArithmeticError, d.count, 2) + d = deque([1, 2, 3]) + self.assertRaises(ArithmeticError, d.count, BadCompare()) + class MutatingCompare: + def __eq__(self, other): + self.d.pop() + return True + m = MutatingCompare() + d = deque([1, 2, 3, m, 4, 5]) + m.d = d + self.assertRaises(RuntimeError, d.count, 3) + def test_comparisons(self): d = deque('xabc'); d.popleft() for e in [d, deque('abc'), deque('ab'), deque(), list(d)]: @@ -576,7 +576,7 @@ Library - Issue #5949: added check for correct lineends in input from IMAP server in imaplib. -- Add a reverse() method to collections.deque(). +- Add count() and reverse() methods to collections.deque(). - Fix variations of extending deques: d.extend(d) d.extendleft(d) d+=d diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index ffb2a80..fa0f004 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -504,6 +504,46 @@ deque_reverse(dequeobject *deque, PyObject *unused) PyDoc_STRVAR(reverse_doc, "D.reverse() -- reverse *IN PLACE*"); +static PyObject * +deque_count(dequeobject *deque, PyObject *v) +{ + block *leftblock = deque->leftblock; + Py_ssize_t leftindex = deque->leftindex; + Py_ssize_t n = (deque->len); + Py_ssize_t i; + Py_ssize_t count = 0; + PyObject *item; + long start_state = deque->state; + int cmp; + + for (i=0 ; i<n ; i++) { + item = leftblock->data[leftindex]; + cmp = PyObject_RichCompareBool(item, v, Py_EQ); + if (cmp > 0) + count++; + else if (cmp < 0) + return NULL; + + if (start_state != deque->state) { + PyErr_SetString(PyExc_RuntimeError, + "deque mutated during iteration"); + return NULL; + } + + /* Advance left block/index pair */ + leftindex++; + if (leftindex == BLOCKLEN) { + assert (leftblock->rightlink != NULL); + leftblock = leftblock->rightlink; + leftindex = 0; + } + } + return PyLong_FromSsize_t(count); +} + +PyDoc_STRVAR(count_doc, +"D.count(value) -> integer -- return number of occurrences of value"); + static Py_ssize_t deque_len(dequeobject *deque) { @@ -933,6 +973,8 @@ static PyMethodDef deque_methods[] = { METH_NOARGS, clear_doc}, {"__copy__", (PyCFunction)deque_copy, METH_NOARGS, copy_doc}, + {"count", (PyCFunction)deque_count, + METH_O, count_doc}, {"extend", (PyCFunction)deque_extend, METH_O, extend_doc}, {"extendleft", (PyCFunction)deque_extendleft, |