diff options
| -rw-r--r-- | Doc/lib/libcollections.tex | 20 | ||||
| -rw-r--r-- | Lib/test/test_deque.py | 12 | ||||
| -rw-r--r-- | Modules/collectionsmodule.c | 97 |
3 files changed, 104 insertions, 25 deletions
diff --git a/Doc/lib/libcollections.tex b/Doc/lib/libcollections.tex index e6ccd7a..ebb2079 100644 --- a/Doc/lib/libcollections.tex +++ b/Doc/lib/libcollections.tex @@ -37,6 +37,17 @@ Deque objects support the following methods: Remove all elements from the deque leaving it with length 0. \end{methoddesc} +\begin{methoddesc}{extend}{iterable} + Extend the right side of the deque by appending elements from + the iterable argument. +\end{methoddesc} + +\begin{methoddesc}{extendleft}{iterable} + Extend the left side of the deque by appending elements from + \var{iterable}. Note, the series of left appends results in + reversing the order of elements in the iterable argument. +\end{methoddesc} + \begin{methoddesc}{pop}{} Remove and return an element from the right side of the deque. If no elements are present, raises a \exception{LookupError}. @@ -75,14 +86,19 @@ deque(['f', 'g', 'h', 'i', 'j']) ['g', 'h', 'i'] >>> 'h' in d # search the deque True ->>> d.__init__('jkl') # use __init__ to append many elements at once +>>> d.extend('jkl') # extend() will append many elements at once >>> d deque(['g', 'h', 'i', 'j', 'k', 'l']) >>> d.clear() # empty the deque ->>> d.pop() # try to pop from an empty deque +>>> d.pop() # cannot pop from an empty deque Traceback (most recent call last): File "<pyshell#6>", line 1, in -toplevel- d.pop() LookupError: pop from an empty deque + +>>> d.extendleft('abc') # extendleft() reverses the element order +>>> d +deque(['c', 'b', 'a']) + \end{verbatim} diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py index 6221c91..51ce7b0 100644 --- a/Lib/test/test_deque.py +++ b/Lib/test/test_deque.py @@ -28,6 +28,18 @@ class TestBasic(unittest.TestCase): self.assertEqual(right, range(150, 400)) self.assertEqual(list(d), range(50, 150)) + def test_extend(self): + d = deque('a') + self.assertRaises(TypeError, d.extend, 1) + d.extend('bcd') + self.assertEqual(list(d), list('abcd')) + + def test_extendleft(self): + d = deque('a') + self.assertRaises(TypeError, d.extendleft, 1) + d.extendleft('bcd') + self.assertEqual(list(d), list(reversed('abcd'))) + def test_len(self): d = deque('ab') self.assertEqual(len(d), 2) diff --git a/Modules/collectionsmodule.c b/Modules/collectionsmodule.c index 6780c57..83be6ac 100644 --- a/Modules/collectionsmodule.c +++ b/Modules/collectionsmodule.c @@ -174,6 +174,72 @@ deque_popleft(dequeobject *deque, PyObject *unused) PyDoc_STRVAR(popleft_doc, "Remove and return the leftmost element."); +static PyObject * +deque_extend(dequeobject *deque, PyObject *iterable) +{ + PyObject *it, *item; + + it = PyObject_GetIter(iterable); + if (it == NULL) + return NULL; + + while ((item = PyIter_Next(it)) != NULL) { + deque->rightindex++; + deque->len++; + if (deque->rightindex == BLOCKLEN) { + block *b = newblock(deque->rightblock, NULL); + if (b == NULL) + return NULL; + assert(deque->rightblock->rightlink == NULL); + deque->rightblock->rightlink = b; + deque->rightblock = b; + deque->rightindex = 0; + } + Py_INCREF(item); + deque->rightblock->data[deque->rightindex] = item; + } + Py_DECREF(it); + if (PyErr_Occurred()) + return NULL; + Py_RETURN_NONE; +} + +PyDoc_STRVAR(extend_doc, +"Extend the right side of the deque with elements from the iterable"); + +static PyObject * +deque_extendleft(dequeobject *deque, PyObject *iterable) +{ + PyObject *it, *item; + + it = PyObject_GetIter(iterable); + if (it == NULL) + return NULL; + + while ((item = PyIter_Next(it)) != NULL) { + deque->leftindex--; + deque->len++; + if (deque->leftindex == -1) { + block *b = newblock(NULL, deque->leftblock); + if (b == NULL) + return NULL; + assert(deque->leftblock->leftlink == NULL); + deque->leftblock->leftlink = b; + deque->leftblock = b; + deque->leftindex = BLOCKLEN - 1; + } + Py_INCREF(item); + deque->leftblock->data[deque->leftindex] = item; + } + Py_DECREF(it); + if (PyErr_Occurred()) + return NULL; + Py_RETURN_NONE; +} + +PyDoc_STRVAR(extendleft_doc, +"Extend the left side of the deque with elements from the iterable"); + static int deque_len(dequeobject *deque) { @@ -356,35 +422,16 @@ deque_tp_print(PyObject *deque, FILE *fp, int flags) static int deque_init(dequeobject *deque, PyObject *args, PyObject *kwds) { - PyObject *iterable = NULL, *it, *item; + PyObject *iterable = NULL; if (!PyArg_UnpackTuple(args, "deque", 0, 1, &iterable)) return -1; if (iterable != NULL) { - it = PyObject_GetIter(iterable); - if (it == NULL) - return -1; - - while ((item = PyIter_Next(it)) != NULL) { - deque->rightindex++; - deque->len++; - if (deque->rightindex == BLOCKLEN) { - block *b = newblock(deque->rightblock, NULL); - if (b == NULL) { - Py_DECREF(it); - Py_DECREF(item); - return -1; - } - deque->rightblock->rightlink = b; - deque->rightblock = b; - deque->rightindex = 0; - } - deque->rightblock->data[deque->rightindex] = item; - } - Py_DECREF(it); - if (PyErr_Occurred()) + PyObject *rv = deque_extend(deque, iterable); + if (rv == NULL) return -1; + Py_DECREF(rv); } return 0; } @@ -413,6 +460,10 @@ static PyMethodDef deque_methods[] = { METH_NOARGS, popleft_doc}, {"__reduce__", (PyCFunction)deque_reduce, METH_NOARGS, reduce_doc}, + {"extend", (PyCFunction)deque_extend, + METH_O, extend_doc}, + {"extendleft", (PyCFunction)deque_extendleft, + METH_O, extendleft_doc}, {NULL, NULL} /* sentinel */ }; |