diff options
| -rw-r--r-- | Lib/test/test_itertools.py | 7 | ||||
| -rw-r--r-- | Misc/NEWS | 2 | ||||
| -rw-r--r-- | Modules/itertoolsmodule.c | 26 |
3 files changed, 34 insertions, 1 deletions
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py index 41e9362..500afef 100644 --- a/Lib/test/test_itertools.py +++ b/Lib/test/test_itertools.py @@ -52,6 +52,13 @@ class TestBasicOps(unittest.TestCase): self.assertEqual(take(4, chain('abc', 'def')), list('abcd')) self.assertRaises(TypeError, list,chain(2, 3)) + def test_chain_from_iterable(self): + self.assertEqual(list(chain.from_iterable(['abc', 'def'])), list('abcdef')) + self.assertEqual(list(chain.from_iterable(['abc'])), list('abc')) + self.assertEqual(list(chain.from_iterable([''])), []) + self.assertEqual(take(4, chain.from_iterable(['abc', 'def'])), list('abcd')) + self.assertRaises(TypeError, list, chain.from_iterable([2, 3])) + def test_combinations(self): self.assertRaises(TypeError, combinations, 'abc') # missing r argument self.assertRaises(TypeError, combinations, 'abc', 2, 1) # too many arguments @@ -1247,6 +1247,8 @@ Extension Modules - itertools.starmap() now accepts any iterable input. Previously, it required the function inputs to be tuples. +- itertools.chain() now has an alterate constructor, chain.from_iterable(). + - Issue #1646: Make socket support TIPC. The socket module now has support for TIPC under Linux, see http://tipc.sf.net/ for more information. diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c index 3b8339c..f29077a 100644 --- a/Modules/itertoolsmodule.c +++ b/Modules/itertoolsmodule.c @@ -1638,6 +1638,18 @@ chain_new(PyTypeObject *type, PyObject *args, PyObject *kwds) return chain_new_internal(type, source); } +static PyObject * +chain_new_from_iterable(PyTypeObject *type, PyObject *arg) +{ + PyObject *source; + + source = PyObject_GetIter(arg); + if (source == NULL) + return NULL; + + return chain_new_internal(type, source); +} + static void chain_dealloc(chainobject *lz) { @@ -1696,6 +1708,18 @@ Return a chain object whose .next() method returns elements from the\n\ first iterable until it is exhausted, then elements from the next\n\ iterable, until all of the iterables are exhausted."); +PyDoc_STRVAR(chain_from_iterable_doc, +"chain.from_iterable(iterable) --> chain object\n\ +\n\ +Alternate chain() contructor taking a single iterable argument\n\ +that evaluates lazily."); + +static PyMethodDef chain_methods[] = { + {"from_iterable", (PyCFunction) chain_new_from_iterable, METH_O | METH_CLASS, + chain_from_iterable_doc}, + {NULL, NULL} /* sentinel */ +}; + static PyTypeObject chain_type = { PyVarObject_HEAD_INIT(NULL, 0) "itertools.chain", /* tp_name */ @@ -1726,7 +1750,7 @@ static PyTypeObject chain_type = { 0, /* tp_weaklistoffset */ PyObject_SelfIter, /* tp_iter */ (iternextfunc)chain_next, /* tp_iternext */ - 0, /* tp_methods */ + chain_methods, /* tp_methods */ 0, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base */ |