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| author | Raymond Hettinger <python@rcn.com> | 2008-01-17 03:02:14 +0000 |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2008-01-17 03:02:14 +0000 |
| commit | 473170908e11e347aca4adf23738a82162b981e3 (patch) | |
| tree | 2fa25a5ccd4abfc71e6a0f5193838a726ce4c68a | |
| parent | 3ad2acc8575e1977cece844b17c572550503a615 (diff) | |
| download | cpython-git-473170908e11e347aca4adf23738a82162b981e3.tar.gz | |
Make starmap() match its pure python definition and accept any itertable input (not just tuples).
| -rw-r--r-- | Doc/library/itertools.rst | 10 | ||||
| -rw-r--r-- | Lib/test/test_itertools.py | 3 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Modules/itertoolsmodule.c | 7 |
4 files changed, 15 insertions, 8 deletions
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index 788d931c28..e797aab6ac 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -330,17 +330,19 @@ loops that truncate the stream. .. function:: starmap(function, iterable) - Make an iterator that computes the function using arguments tuples obtained from + Make an iterator that computes the function using arguments obtained from the iterable. Used instead of :func:`imap` when argument parameters are already grouped in tuples from a single iterable (the data has been "pre-zipped"). The difference between :func:`imap` and :func:`starmap` parallels the distinction between ``function(a,b)`` and ``function(*c)``. Equivalent to:: def starmap(function, iterable): - iterable = iter(iterable) - while True: - yield function(*iterable.next()) + for args in iterable: + yield function(*args) + .. versionchanged:: 2.6 + Previously, :func:`starmap` required the function arguments to be tuples. + Now, any iterable is allowed. .. function:: takewhile(predicate, iterable) diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py index 1a3064c305..9d1922823d 100644 --- a/Lib/test/test_itertools.py +++ b/Lib/test/test_itertools.py @@ -292,7 +292,8 @@ class TestBasicOps(unittest.TestCase): self.assertEqual(take(3, starmap(operator.pow, izip(count(), count(1)))), [0**1, 1**2, 2**3]) self.assertEqual(list(starmap(operator.pow, [])), []) - self.assertRaises(TypeError, list, starmap(operator.pow, [[4,5]])) + self.assertEqual(list(starmap(operator.pow, [iter([4,5])])), [4**5]) + self.assertRaises(TypeError, list, starmap(operator.pow, [None])) self.assertRaises(TypeError, starmap) self.assertRaises(TypeError, starmap, operator.pow, [(4,5)], 'extra') self.assertRaises(TypeError, starmap(10, [(4,5)]).next) @@ -993,6 +993,9 @@ Extension Modules the context manager protocol. The _winreg module also gained a new function ``ExpandEnvironmentStrings`` to expand REG_EXPAND_SZ keys. +- itertools.starmap() now accepts any iterable input. Previously, it required + the function inputs to be tuples. + - 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 ebb4deb268..430313eaa6 100644 --- a/Modules/itertoolsmodule.c +++ b/Modules/itertoolsmodule.c @@ -1356,10 +1356,11 @@ starmap_next(starmapobject *lz) if (args == NULL) return NULL; if (!PyTuple_CheckExact(args)) { + PyObject *newargs = PySequence_Tuple(args); Py_DECREF(args); - PyErr_SetString(PyExc_TypeError, - "iterator must return a tuple"); - return NULL; + if (newargs == NULL) + return NULL; + args = newargs; } result = PyObject_Call(lz->func, args, NULL); Py_DECREF(args); |