Merged revisions 61038,61042-61045,61047,61050,61053,61055-61056,61061-61062,61066,61068,61070,61081-61095 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r61081 | neal.norwitz | 2008-02-26 09:04:59 +0100 (Tue, 26 Feb 2008) | 7 lines

  Speed up this test by about 99%.  Remove sleeps and replace with events.
  (This may fail on some slow platforms, but we can fix those cases which
  should be relatively isolated and easier to find now.)
  Move two test cases that didn't require a server to be started
  to a separate TestCase.  These tests were taking 3 seconds which
  is what the timeout was set to.
........
  r61082 | christian.heimes | 2008-02-26 09:18:11 +0100 (Tue, 26 Feb 2008) | 1 line

  The contains function raised a gcc warning. The new code is copied straight from py3k.
........
  r61084 | neal.norwitz | 2008-02-26 09:21:28 +0100 (Tue, 26 Feb 2008) | 3 lines

  Add a timing flag to Trace so you can see where slowness occurs
  like waiting for socket timeouts in test_smtplib :-).
........
  r61086 | christian.heimes | 2008-02-26 18:23:51 +0100 (Tue, 26 Feb 2008) | 3 lines

  Patch #1691070 from Roger Upole: Speed up PyArg_ParseTupleAndKeywords() and improve error msg
  My tests don't show the promised speed up of 10%. The code is as fast as the old code for simple cases and slightly faster for complex cases with several of args and kwargs. But the patch simplifies the code, too.
........
  r61087 | georg.brandl | 2008-02-26 20:13:45 +0100 (Tue, 26 Feb 2008) | 2 lines

  #2194: fix some typos.
........
  r61088 | raymond.hettinger | 2008-02-27 00:40:50 +0100 (Wed, 27 Feb 2008) | 1 line

  Add itertools.combinations().
........
  r61089 | raymond.hettinger | 2008-02-27 02:08:04 +0100 (Wed, 27 Feb 2008) | 1 line

  One too many decrefs.
........
  r61090 | raymond.hettinger | 2008-02-27 02:08:30 +0100 (Wed, 27 Feb 2008) | 1 line

  Larger test range
........
  r61091 | raymond.hettinger | 2008-02-27 02:44:34 +0100 (Wed, 27 Feb 2008) | 1 line

  Simply the sample code for combinations().
........

11 files changed, 510 insertions, 245 deletions

diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index d04f33b..826fa45 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -95,21 +95,20 @@ loops that truncate the stream.
 
         def combinations(iterable, r):
             pool = tuple(iterable)
-            if pool:
-                n = len(pool)
-                vec = range(r)
-                yield tuple(pool[i] for i in vec)
-                while 1:
-                    for i in reversed(range(r)):
-                        if vec[i] == i + n-r:
-                            continue
-                        vec[i] += 1
-                        for j in range(i+1, r):
-                            vec[j] = vec[j-1] + 1
-                        yield tuple(pool[i] for i in vec)
+            n = len(pool)
+            assert 0 <= r <= n
+            vec = range(r)
+            yield tuple(pool[i] for i in vec)
+            while 1:
+                for i in reversed(range(r)):
+                    if vec[i] != i + n - r:
                         break
-                    else:
-                        return
+                else:
+                    return
+                vec[i] += 1
+                for j in range(i+1, r):
+                    vec[j] = vec[j-1] + 1
+                yield tuple(pool[i] for i in vec)
 
    .. versionadded:: 2.6
 
diff --git a/Doc/library/trace.rst b/Doc/library/trace.rst
index 9d0c0c4..05d5d66 100644
--- a/Doc/library/trace.rst
+++ b/Doc/library/trace.rst
@@ -80,7 +80,7 @@ Programming Interface
 ---------------------
 
 
-.. class:: Trace([count=1[, trace=1[, countfuncs=0[, countcallers=0[, ignoremods=()[, ignoredirs=()[, infile=None[, outfile=None]]]]]]]])
+.. class:: Trace([count=1[, trace=1[, countfuncs=0[, countcallers=0[, ignoremods=()[, ignoredirs=()[, infile=None[, outfile=None[, timing=False]]]]]]]]])
 
    Create an object to trace execution of a single statement or expression. All
    parameters are optional.  *count* enables counting of line numbers. *trace*
@@ -89,7 +89,8 @@ Programming Interface
    *ignoremods* is a list of modules or packages to ignore.  *ignoredirs* is a list
    of directories whose modules or packages should be ignored.  *infile* is the
    file from which to read stored count information.  *outfile* is a file in which
-   to write updated count information.
+   to write updated count information. *timing* enables a timestamp relative
+   to when tracing was started to be displayed.
 
 
 .. method:: Trace.run(cmd)
diff --git a/Doc/using/unix.rst b/Doc/using/unix.rst
index cc99a62..69b76c6 100644
--- a/Doc/using/unix.rst
+++ b/Doc/using/unix.rst
@@ -20,7 +20,7 @@ package on all others.  However there are certain features you might want to use
 that are not available on your distro's package.  You can easily compile the
 latest version of Python from source.
 	
-In the event Python doesn't come preinstalled and isn't in the repositories as
+In the event that Python doesn't come preinstalled and isn't in the repositories as
 well, you can easily make packages for your own distro.  Have a look at the
 following links:
 
diff --git a/Doc/using/windows.rst b/Doc/using/windows.rst
index 1753b6d..cd706a7 100644
--- a/Doc/using/windows.rst
+++ b/Doc/using/windows.rst
@@ -21,7 +21,7 @@ has compiled Windows installers (MSI packages) with every `release
 <http://www.python.org/download/releases/>`_ for many years.
 
 With ongoing development of Python, some platforms that used to be supported
-earlier are not longer supported (due to the lack of users or developers).
+earlier are no longer supported (due to the lack of users or developers).
 Check :pep:`11` for details on all unsupported platforms.
 
 * DOS and Windows 3.x are deprecated since Python 2.0 and code specific to these
diff --git a/Lib/test/test_getargs2.py b/Lib/test/test_getargs2.py
index 4253141..1918386 100644
--- a/Lib/test/test_getargs2.py
+++ b/Lib/test/test_getargs2.py
@@ -1,5 +1,6 @@
 import unittest
 from test import test_support
+from _testcapi import getargs_keywords
 
 import warnings
 warnings.filterwarnings("ignore",
@@ -248,9 +249,57 @@ class Tuple_TestCase(unittest.TestCase):
                 raise ValueError
         self.assertRaises(TypeError, getargs_tuple, 1, seq())
 
+class Keywords_TestCase(unittest.TestCase):
+    def test_positional_args(self):
+        # using all positional args
+        self.assertEquals(
+            getargs_keywords((1,2), 3, (4,(5,6)), (7,8,9), 10),
+            (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+            )
+    def test_mixed_args(self):
+        # positional and keyword args
+        self.assertEquals(
+            getargs_keywords((1,2), 3, (4,(5,6)), arg4=(7,8,9), arg5=10),
+            (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+            )
+    def test_keyword_args(self):
+        # all keywords
+        self.assertEquals(
+            getargs_keywords(arg1=(1,2), arg2=3, arg3=(4,(5,6)), arg4=(7,8,9), arg5=10),
+            (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+            )
+    def test_optional_args(self):
+        # missing optional keyword args, skipping tuples
+        self.assertEquals(
+            getargs_keywords(arg1=(1,2), arg2=3, arg5=10),
+            (1, 2, 3, -1, -1, -1, -1, -1, -1, 10)
+            )
+    def test_required_args(self):
+        # required arg missing
+        try:
+            getargs_keywords(arg1=(1,2))
+        except TypeError as err:
+            self.assertEquals(str(err), "Required argument 'arg2' (pos 2) not found")
+        else:
+            self.fail('TypeError should have been raised')
+    def test_too_many_args(self):
+        try:
+            getargs_keywords((1,2),3,(4,(5,6)),(7,8,9),10,111)
+        except TypeError as err:
+            self.assertEquals(str(err), "function takes at most 5 arguments (6 given)")
+        else:
+            self.fail('TypeError should have been raised')
+    def test_invalid_keyword(self):
+        # extraneous keyword arg
+        try:
+            getargs_keywords((1,2),3,arg5=10,arg666=666)
+        except TypeError as err:
+            self.assertEquals(str(err), "'arg666' is an invalid keyword argument for this function")
+        else:
+            self.fail('TypeError should have been raised')
 
 def test_main():
-    tests = [Signed_TestCase, Unsigned_TestCase, Tuple_TestCase]
+    tests = [Signed_TestCase, Unsigned_TestCase, Tuple_TestCase, Keywords_TestCase]
     try:
         from _testcapi import getargs_L, getargs_K
     except ImportError:
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 63ca17b..ba726b5 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -44,6 +44,10 @@ def take(n, seq):
     'Convenience function for partially consuming a long of infinite iterable'
     return list(islice(seq, n))
 
+def fact(n):
+    'Factorial'
+    return reduce(operator.mul, range(1, n+1), 1)
+
 class TestBasicOps(unittest.TestCase):
     def test_chain(self):
         self.assertEqual(list(chain('abc', 'def')), list('abcdef'))
@@ -52,6 +56,26 @@ class TestBasicOps(unittest.TestCase):
         self.assertEqual(take(4, chain('abc', 'def')), list('abcd'))
         self.assertRaises(TypeError, chain, 2, 3)
 
+    def test_combinations(self):
+        self.assertRaises(TypeError, combinations, 'abc')   # missing r argument
+        self.assertRaises(TypeError, combinations, 'abc', 2, 1) # too many arguments
+        self.assertRaises(ValueError, combinations, 'abc', -2)  # r is negative
+        self.assertRaises(ValueError, combinations, 'abc', 32)  # r is too big
+        self.assertEqual(list(combinations(range(4), 3)),
+                                           [(0,1,2), (0,1,3), (0,2,3), (1,2,3)])
+        for n in range(8):
+            values = [5*x-12 for x in range(n)]
+            for r in range(n+1):
+                result = list(combinations(values, r))
+                self.assertEqual(len(result), fact(n) / fact(r) / fact(n-r)) # right number of combs
+                self.assertEqual(len(result), len(set(result)))         # no repeats
+                self.assertEqual(result, sorted(result))                # lexicographic order
+                for c in result:
+                    self.assertEqual(len(c), r)                         # r-length combinations
+                    self.assertEqual(len(set(c)), r)                    # no duplicate elements
+                    self.assertEqual(list(c), sorted(c))                # keep original ordering
+                    self.assert_(all(e in values for e in c))           # elements taken from input iterable
+
     def test_count(self):
         self.assertEqual(lzip('abc',count()), [('a', 0), ('b', 1), ('c', 2)])
         self.assertEqual(lzip('abc',count(3)), [('a', 3), ('b', 4), ('c', 5)])
diff --git a/Lib/test/test_smtplib.py b/Lib/test/test_smtplib.py
index 6b00b80..5694bb5 100644
--- a/Lib/test/test_smtplib.py
+++ b/Lib/test/test_smtplib.py
@@ -18,14 +18,15 @@ HOST = "localhost"
 PORT = None
 
 def server(evt, buf):
+    serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    serv.settimeout(1)
+    serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    serv.bind(("", 0))
+    global PORT
+    PORT = serv.getsockname()[1]
+    serv.listen(5)
+    evt.set()
     try:
-        serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        serv.settimeout(3)
-        serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        serv.bind(("", 0))
-        global PORT
-        PORT = serv.getsockname()[1]
-        serv.listen(5)
         conn, addr = serv.accept()
     except socket.timeout:
         pass
@@ -38,7 +39,6 @@ def server(evt, buf):
                 buf = buf[sent:]
 
             n -= 1
-            time.sleep(0.01)
 
         conn.close()
     finally:
@@ -52,16 +52,8 @@ class GeneralTests(TestCase):
         self.evt = threading.Event()
         servargs = (self.evt, b"220 Hola mundo\n")
         threading.Thread(target=server, args=servargs).start()
-
-        # wait until server thread has assigned a port number
-        n = 500
-        while PORT is None and n > 0:
-            time.sleep(0.01)
-            n -= 1
-
-        # wait a little longer (sometimes connections are refused
-        # on slow machines without this additional wait)
-        time.sleep(0.5)
+        self.evt.wait()
+        self.evt.clear()
 
     def tearDown(self):
         self.evt.wait()
@@ -76,29 +68,12 @@ class GeneralTests(TestCase):
         smtp = smtplib.SMTP("%s:%s" % (HOST, PORT))
         smtp.sock.close()
 
-    def testNotConnected(self):
-        # Test various operations on an unconnected SMTP object that
-        # should raise exceptions (at present the attempt in SMTP.send
-        # to reference the nonexistent 'sock' attribute of the SMTP object
-        # causes an AttributeError)
-        smtp = smtplib.SMTP()
-        self.assertRaises(smtplib.SMTPServerDisconnected, smtp.ehlo)
-        self.assertRaises(smtplib.SMTPServerDisconnected,
-                          smtp.send, 'test msg')
-
     def testLocalHostName(self):
         # check that supplied local_hostname is used
         smtp = smtplib.SMTP(HOST, PORT, local_hostname="testhost")
         self.assertEqual(smtp.local_hostname, "testhost")
         smtp.sock.close()
 
-    def testNonnumericPort(self):
-        # check that non-numeric port raises socket.error
-        self.assertRaises(socket.error, smtplib.SMTP,
-                          "localhost", "bogus")
-        self.assertRaises(socket.error, smtplib.SMTP,
-                          "localhost:bogus")
-
     def testTimeoutDefault(self):
         # default
         smtp = smtplib.SMTP(HOST, PORT)
@@ -128,6 +103,7 @@ def debugging_server(server_class, serv_evt, client_evt):
     serv = server_class(("", 0), ('nowhere', -1))
     global PORT
     PORT = serv.getsockname()[1]
+    serv_evt.set()
 
     try:
         if hasattr(select, 'poll'):
@@ -150,12 +126,12 @@ def debugging_server(server_class, serv_evt, client_evt):
     except socket.timeout:
         pass
     finally:
-        # allow some time for the client to read the result
-        time.sleep(0.5)
-        serv.close()
+        if not client_evt.isSet():
+            # allow some time for the client to read the result
+            time.sleep(0.5)
+            serv.close()
         asyncore.close_all()
         PORT = None
-        time.sleep(0.5)
         serv_evt.set()
 
 MSG_BEGIN = '---------- MESSAGE FOLLOWS ----------\n'
@@ -181,14 +157,8 @@ class DebuggingServerTests(TestCase):
         threading.Thread(target=debugging_server, args=serv_args).start()
 
         # wait until server thread has assigned a port number
-        n = 500
-        while PORT is None and n > 0:
-            time.sleep(0.01)
-            n -= 1
-
-        # wait a little longer (sometimes connections are refused
-        # on slow machines without this additional wait)
-        time.sleep(0.5)
+        self.serv_evt.wait()
+        self.serv_evt.clear()
 
     def tearDown(self):
         # indicate that the client is finished
@@ -258,6 +228,26 @@ class DebuggingServerTests(TestCase):
         self.assertEqual(self.output.getvalue(), mexpect)
 
 
+class NonConnectingTests(TestCase):
+
+    def testNotConnected(self):
+        # Test various operations on an unconnected SMTP object that
+        # should raise exceptions (at present the attempt in SMTP.send
+        # to reference the nonexistent 'sock' attribute of the SMTP object
+        # causes an AttributeError)
+        smtp = smtplib.SMTP()
+        self.assertRaises(smtplib.SMTPServerDisconnected, smtp.ehlo)
+        self.assertRaises(smtplib.SMTPServerDisconnected,
+                          smtp.send, 'test msg')
+
+    def testNonnumericPort(self):
+        # check that non-numeric port raises socket.error
+        self.assertRaises(socket.error, smtplib.SMTP,
+                          "localhost", "bogus")
+        self.assertRaises(socket.error, smtplib.SMTP,
+                          "localhost:bogus")
+
+
 # test response of client to a non-successful HELO message
 class BadHELOServerTests(TestCase):
 
@@ -269,16 +259,8 @@ class BadHELOServerTests(TestCase):
         self.evt = threading.Event()
         servargs = (self.evt, b"199 no hello for you!\n")
         threading.Thread(target=server, args=servargs).start()
-
-        # wait until server thread has assigned a port number
-        n = 500
-        while PORT is None and n > 0:
-            time.sleep(0.01)
-            n -= 1
-
-        # wait a little longer (sometimes connections are refused
-        # on slow machines without this additional wait)
-        time.sleep(0.5)
+        self.evt.wait()
+        self.evt.clear()
 
     def tearDown(self):
         self.evt.wait()
@@ -355,14 +337,8 @@ class SMTPSimTests(TestCase):
         threading.Thread(target=debugging_server, args=serv_args).start()
 
         # wait until server thread has assigned a port number
-        n = 500
-        while PORT is None and n > 0:
-            time.sleep(0.01)
-            n -= 1
-
-        # wait a little longer (sometimes connections are refused
-        # on slow machines without this additional wait)
-        time.sleep(0.5)
+        self.serv_evt.wait()
+        self.serv_evt.clear()
 
     def tearDown(self):
         # indicate that the client is finished
@@ -430,6 +406,7 @@ class SMTPSimTests(TestCase):
 
 def test_main(verbose=None):
     test_support.run_unittest(GeneralTests, DebuggingServerTests,
+                              NonConnectingTests,
                               BadHELOServerTests, SMTPSimTests)
 
 if __name__ == '__main__':
diff --git a/Lib/trace.py b/Lib/trace.py
index c52c8a8..06b72b7 100644
--- a/Lib/trace.py
+++ b/Lib/trace.py
@@ -53,6 +53,7 @@ import os
 import re
 import sys
 import threading
+import time
 import token
 import tokenize
 import types
@@ -94,6 +95,8 @@ Modifiers:
                       with '>>>>>> '.
 -s, --summary         Write a brief summary on stdout for each file.
                       (Can only be used with --count or --report.)
+-g, --timing          Prefix each line with the time since the program started.
+                      Only used while tracing.
 
 Filters, may be repeated multiple times:
 --ignore-module=<mod> Ignore the given module(s) and its submodules
@@ -431,7 +434,8 @@ def find_executable_linenos(filename):
 
 class Trace:
     def __init__(self, count=1, trace=1, countfuncs=0, countcallers=0,
-                 ignoremods=(), ignoredirs=(), infile=None, outfile=None):
+                 ignoremods=(), ignoredirs=(), infile=None, outfile=None,
+                 timing=False):
         """
         @param count true iff it should count number of times each
                      line is executed
@@ -447,6 +451,7 @@ class Trace:
         @param infile file from which to read stored counts to be
                      added into the results
         @param outfile file in which to write the results
+        @param timing true iff timing information be displayed
         """
         self.infile = infile
         self.outfile = outfile
@@ -459,6 +464,9 @@ class Trace:
         self._calledfuncs = {}
         self._callers = {}
         self._caller_cache = {}
+        self.start_time = None
+        if timing:
+            self.start_time = time.time()
         if countcallers:
             self.globaltrace = self.globaltrace_trackcallers
         elif countfuncs:
@@ -609,6 +617,8 @@ class Trace:
             key = filename, lineno
             self.counts[key] = self.counts.get(key, 0) + 1
 
+            if self.start_time:
+                print('%.2f' % (time.time() - self.start_time), end=' ')
             bname = os.path.basename(filename)
             print("%s(%d): %s" % (bname, lineno,
                                   linecache.getline(filename, lineno)), end=' ')
@@ -620,6 +630,8 @@ class Trace:
             filename = frame.f_code.co_filename
             lineno = frame.f_lineno
 
+            if self.start_time:
+                print('%.2f' % (time.time() - self.start_time), end=' ')
             bname = os.path.basename(filename)
             print("%s(%d): %s" % (bname, lineno,
                                   linecache.getline(filename, lineno)), end=' ')
@@ -649,13 +661,13 @@ def main(argv=None):
     if argv is None:
         argv = sys.argv
     try:
-        opts, prog_argv = getopt.getopt(argv[1:], "tcrRf:d:msC:lT",
+        opts, prog_argv = getopt.getopt(argv[1:], "tcrRf:d:msC:lTg",
                                         ["help", "version", "trace", "count",
                                          "report", "no-report", "summary",
                                          "file=", "missing",
                                          "ignore-module=", "ignore-dir=",
                                          "coverdir=", "listfuncs",
-                                         "trackcalls"])
+                                         "trackcalls", "timing"])
 
     except getopt.error as msg:
         sys.stderr.write("%s: %s\n" % (sys.argv[0], msg))
@@ -675,6 +687,7 @@ def main(argv=None):
     summary = 0
     listfuncs = False
     countcallers = False
+    timing = False
 
     for opt, val in opts:
         if opt == "--help":
@@ -693,6 +706,10 @@ def main(argv=None):
             listfuncs = True
             continue
 
+        if opt == "-g" or opt == "--timing":
+            timing = True
+            continue
+
         if opt == "-t" or opt == "--trace":
             trace = 1
             continue
@@ -775,7 +792,7 @@ def main(argv=None):
         t = Trace(count, trace, countfuncs=listfuncs,
                   countcallers=countcallers, ignoremods=ignore_modules,
                   ignoredirs=ignore_dirs, infile=counts_file,
-                  outfile=counts_file)
+                  outfile=counts_file, timing=timing)
         try:
             fp = open(progname)
             try:
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index c462d69..45184c6 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -308,6 +308,22 @@ getargs_tuple(PyObject *self, PyObject *args)
 	return Py_BuildValue("iii", a, b, c);
 }
 
+/* test PyArg_ParseTupleAndKeywords */
+static PyObject *getargs_keywords(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+	static char *keywords[] = {"arg1","arg2","arg3","arg4","arg5", NULL};
+	static char *fmt="(ii)i|(i(ii))(iii)i";
+	int int_args[10]={-1, -1, -1, -1, -1, -1, -1, -1, -1, -1};
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, fmt, keywords,
+		&int_args[0], &int_args[1], &int_args[2], &int_args[3], &int_args[4],
+		&int_args[5], &int_args[6], &int_args[7], &int_args[8], &int_args[9]))
+		return NULL;
+	return Py_BuildValue("iiiiiiiiii",
+		int_args[0], int_args[1], int_args[2], int_args[3], int_args[4],
+		int_args[5], int_args[6], int_args[7], int_args[8], int_args[9]);
+}
+
 /* Functions to call PyArg_ParseTuple with integer format codes,
    and return the result.
 */
@@ -898,6 +914,8 @@ static PyMethodDef TestMethods[] = {
 	 PyDoc_STR("This is a pretty normal docstring.")},
 
 	{"getargs_tuple",	getargs_tuple,			 METH_VARARGS},
+	{"getargs_keywords", (PyCFunction)getargs_keywords, 
+	  METH_VARARGS|METH_KEYWORDS},
 	{"getargs_b",		getargs_b,			 METH_VARARGS},
 	{"getargs_B",		getargs_B,			 METH_VARARGS},
 	{"getargs_H",		getargs_H,			 METH_VARARGS},
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 5c8e86f..fa73605 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -1764,10 +1764,8 @@ product_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 
 	/* create productobject structure */
 	lz = (productobject *)type->tp_alloc(type, 0);
-	if (lz == NULL) {
-		Py_DECREF(pools);
+	if (lz == NULL)
 		goto error;
-	}
 
 	lz->pools = pools;
 	lz->maxvec = maxvec;
@@ -1952,6 +1950,232 @@ static PyTypeObject product_type = {
 };
 
 
+/* combinations object ************************************************************/
+
+typedef struct {
+	PyObject_HEAD
+	PyObject *pool;			/* input converted to a tuple */
+	Py_ssize_t *indices;            /* one index per result element */
+	PyObject *result;               /* most recently returned result tuple */
+	Py_ssize_t r;			/* size of result tuple */
+	int stopped;			/* set to 1 when the combinations iterator is exhausted */
+} combinationsobject;
+
+static PyTypeObject combinations_type;
+
+static PyObject *
+combinations_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+	combinationsobject *co;
+	Py_ssize_t n;
+	Py_ssize_t r;
+	PyObject *pool = NULL;
+	PyObject *iterable = NULL;
+	Py_ssize_t *indices = NULL;
+	Py_ssize_t i;
+	static char *kwargs[] = {"iterable", "r", NULL};
+ 
+ 	if (!PyArg_ParseTupleAndKeywords(args, kwds, "On:combinations", kwargs, 
+					 &iterable, &r))
+		return NULL;
+
+	pool = PySequence_Tuple(iterable);
+	if (pool == NULL)
+		goto error;
+	n = PyTuple_GET_SIZE(pool);
+	if (r < 0) {
+		PyErr_SetString(PyExc_ValueError, "r must be non-negative");
+		goto error;
+	}
+	if (r > n) {
+		PyErr_SetString(PyExc_ValueError, "r cannot be bigger than the iterable");
+		goto error;
+	}
+
+	indices = PyMem_Malloc(r * sizeof(Py_ssize_t));
+	if (indices == NULL) {
+    		PyErr_NoMemory();
+		goto error;
+	}
+
+	for (i=0 ; i<r ; i++)
+		indices[i] = i;
+
+	/* create combinationsobject structure */
+	co = (combinationsobject *)type->tp_alloc(type, 0);
+	if (co == NULL)
+		goto error;
+
+	co->pool = pool;
+	co->indices = indices;
+	co->result = NULL;
+	co->r = r;
+	co->stopped = 0;
+
+	return (PyObject *)co;
+
+error:
+	if (indices != NULL)
+		PyMem_Free(indices);
+	Py_XDECREF(pool);
+	return NULL;
+}
+
+static void
+combinations_dealloc(combinationsobject *co)
+{
+	PyObject_GC_UnTrack(co);
+	Py_XDECREF(co->pool);
+	Py_XDECREF(co->result);
+	PyMem_Free(co->indices);
+	Py_TYPE(co)->tp_free(co);
+}
+
+static int
+combinations_traverse(combinationsobject *co, visitproc visit, void *arg)
+{
+	Py_VISIT(co->pool);
+	Py_VISIT(co->result);
+	return 0;
+}
+
+static PyObject *
+combinations_next(combinationsobject *co)
+{
+	PyObject *elem;
+	PyObject *oldelem;
+	PyObject *pool = co->pool;
+	Py_ssize_t *indices = co->indices;
+	PyObject *result = co->result;
+	Py_ssize_t n = PyTuple_GET_SIZE(pool);
+	Py_ssize_t r = co->r;
+	Py_ssize_t i, j, index;
+
+	if (co->stopped)
+		return NULL;
+
+	if (result == NULL) {
+                /* On the first pass, initialize result tuple using the indices */
+		result = PyTuple_New(r);
+		if (result == NULL)
+            		goto empty;
+		co->result = result;
+		for (i=0; i<r ; i++) {
+			index = indices[i];
+    			elem = PyTuple_GET_ITEM(pool, index);
+    			Py_INCREF(elem);
+    			PyTuple_SET_ITEM(result, i, elem);
+		}
+	} else {
+		/* Copy the previous result tuple or re-use it if available */
+		if (Py_REFCNT(result) > 1) {
+			PyObject *old_result = result;
+			result = PyTuple_New(r);
+			if (result == NULL)
+				goto empty;
+			co->result = result;
+			for (i=0; i<r ; i++) {
+				elem = PyTuple_GET_ITEM(old_result, i);
+    				Py_INCREF(elem);
+    				PyTuple_SET_ITEM(result, i, elem);
+			}
+			Py_DECREF(old_result);
+		}
+		/* Now, we've got the only copy so we can update it in-place
+		 * CPython's empty tuple is a singleton and cached in
+		 * PyTuple's freelist.
+		 */
+		assert(r == 0 || Py_REFCNT(result) == 1);
+
+                /* Scan indices right-to-left until finding one that is not
+                   at its maximum (i + n - r). */
+		for (i=r-1 ; i >= 0 && indices[i] == i+n-r ; i--)
+			;
+
+		/* If i is negative, then the indices are all at
+                   their maximum value and we're done. */
+		if (i < 0)
+			goto empty;
+
+		/* Increment the current index which we know is not at its
+                   maximum.  Then move back to the right setting each index
+                   to its lowest possible value (one higher than the index
+                   to its left -- this maintains the sort order invariant). */
+		indices[i]++;
+		for (j=i+1 ; j<r ; j++)
+			indices[j] = indices[j-1] + 1;
+
+		/* Update the result tuple for the new indices
+		   starting with i, the leftmost index that changed */
+		for ( ; i<r ; i++) {
+			index = indices[i];
+			elem = PyTuple_GET_ITEM(pool, index);
+			Py_INCREF(elem);
+			oldelem = PyTuple_GET_ITEM(result, i);
+			PyTuple_SET_ITEM(result, i, elem);
+			Py_DECREF(oldelem);
+		}
+	}
+
+	Py_INCREF(result);
+	return result;
+
+empty:
+	co->stopped = 1;
+	return NULL;
+}
+
+PyDoc_STRVAR(combinations_doc,
+"combinations(iterables) --> combinations object\n\
+\n\
+Return successive r-length combinations of elements in the iterable.\n\n\
+combinations(range(4), 3) --> (0,1,2), (0,1,3), (0,2,3), (1,2,3)");
+
+static PyTypeObject combinations_type = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	"itertools.combinations",		/* tp_name */
+	sizeof(combinationsobject),	/* tp_basicsize */
+	0,				/* tp_itemsize */
+	/* methods */
+	(destructor)combinations_dealloc,	/* tp_dealloc */
+	0,				/* tp_print */
+	0,				/* tp_getattr */
+	0,				/* tp_setattr */
+	0,				/* tp_compare */
+	0,				/* tp_repr */
+	0,				/* tp_as_number */
+	0,				/* tp_as_sequence */
+	0,				/* tp_as_mapping */
+	0,				/* tp_hash */
+	0,				/* tp_call */
+	0,				/* tp_str */
+	PyObject_GenericGetAttr,	/* tp_getattro */
+	0,				/* tp_setattro */
+	0,				/* tp_as_buffer */
+	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+		Py_TPFLAGS_BASETYPE,	/* tp_flags */
+	combinations_doc,			/* tp_doc */
+	(traverseproc)combinations_traverse,	/* tp_traverse */
+	0,				/* tp_clear */
+	0,				/* tp_richcompare */
+	0,				/* tp_weaklistoffset */
+	PyObject_SelfIter,		/* tp_iter */
+	(iternextfunc)combinations_next,	/* tp_iternext */
+	0,				/* tp_methods */
+	0,				/* tp_members */
+	0,				/* tp_getset */
+	0,				/* tp_base */
+	0,				/* tp_dict */
+	0,				/* tp_descr_get */
+	0,				/* tp_descr_set */
+	0,				/* tp_dictoffset */
+	0,				/* tp_init */
+	0,				/* tp_alloc */
+	combinations_new,			/* tp_new */
+	PyObject_GC_Del,		/* tp_free */
+};
+
+
 /* ifilter object ************************************************************/
 
 typedef struct {
@@ -2978,6 +3202,7 @@ inititertools(void)
 	PyObject *m;
 	char *name;
 	PyTypeObject *typelist[] = {
+		&combinations_type,
 		&cycle_type,
 		&dropwhile_type,
 		&takewhile_type,
@@ -2990,7 +3215,7 @@ inititertools(void)
 		&count_type,
 		&izip_type,
 		&iziplongest_type,
-		&product_type,          
+		&product_type,         
 		&repeat_type,
 		&groupby_type,
 		NULL
diff --git a/Python/getargs.c b/Python/getargs.c
index c0b3624..abe0887 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -1401,6 +1401,7 @@ _PyArg_VaParseTupleAndKeywords_SizeT(PyObject *args,
 	return retval;
 }
 
+#define IS_END_OF_FORMAT(c) (c == '\0' || c == ';' || c == ':')
 
 static int
 vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
@@ -1408,13 +1409,10 @@ vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
 {
 	char msgbuf[512];
 	int levels[32];
-	const char *fname, *message;
-	int min, max;
-	const char *formatsave;
+	const char *fname, *msg, *custom_msg, *keyword;
+	int min = INT_MAX;
 	int i, len, nargs, nkeywords;
-	const char *msg;
-	char **p;
-	PyObject *freelist = NULL;
+	PyObject *freelist = NULL, *current_arg;
 
 	assert(args != NULL && PyTuple_Check(args));
 	assert(keywords == NULL || PyDict_Check(keywords));
@@ -1422,168 +1420,108 @@ vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
 	assert(kwlist != NULL);
 	assert(p_va != NULL);
 
-	/* Search the format:
-	   message <- error msg, if any (else NULL).
-	   fname <- routine name, if any (else NULL).
-	   min <- # of required arguments, or -1 if all are required.
-	   max <- most arguments (required + optional).
-	   Check that kwlist has a non-NULL entry for each arg.
-	   Raise error if a tuple arg spec is found.
-	*/
-	fname = message = NULL;
-	formatsave = format;
-	p = kwlist;
-	min = -1;
-	max = 0;
-	while ((i = *format++) != '\0') {
-		if (isalpha(Py_CHARMASK(i)) && i != 'e') {
-			max++;
-			if (*p == NULL) {
-				PyErr_SetString(PyExc_RuntimeError,
-					"more argument specifiers than "
-					"keyword list entries");
-				return 0;
-			}
-			p++;
-		}
-		else if (i == '|')
-			min = max;
-		else if (i == ':') {
-			fname = format;
-			break;
-		}
-		else if (i == ';') {
-			message = format;
-			break;
-		}
-		else if (i == '(') {
-			PyErr_SetString(PyExc_RuntimeError,
-				"tuple found in format when using keyword "
-				"arguments");
-			return 0;
-		}
-	}
-	format = formatsave;
-	if (*p != NULL) {
-		PyErr_SetString(PyExc_RuntimeError,
-			"more keyword list entries than "
-			"argument specifiers");
-		return 0;
-	}
-	if (min < 0) {
-		/* All arguments are required. */
-		min = max;
+	/* grab the function name or custom error msg first (mutually exclusive) */
+	fname = strchr(format, ':');
+	if (fname) {
+		fname++;
+		custom_msg = NULL;
 	}
-
-	nargs = PyTuple_GET_SIZE(args);
-	nkeywords = keywords == NULL ? 0 : PyDict_Size(keywords);
-
-	/* make sure there are no duplicate values for an argument;
-	   its not clear when to use the term "keyword argument vs.
-	   keyword parameter in messages */
-	if (nkeywords > 0) {
-		for (i = 0; i < nargs; i++) {
-			const char *thiskw = kwlist[i];
-			if (thiskw == NULL)
-				break;
-			if (PyDict_GetItemString(keywords, thiskw)) {
-				PyErr_Format(PyExc_TypeError,
-					"keyword parameter '%s' was given "
-					"by position and by name",
-					thiskw);
-				return 0;
-			}
-			else if (PyErr_Occurred())
-				return 0;
-		}
+	else {
+		custom_msg = strchr(format,';');
+		if (custom_msg)
+			custom_msg++;
 	}
 
-	/* required arguments missing from args can be supplied by keyword
-	   arguments; set len to the number of positional arguments, and,
-	   if that's less than the minimum required, add in the number of
-	   required arguments that are supplied by keywords */
-	len = nargs;
-	if (nkeywords > 0 && nargs < min) {
-		for (i = nargs; i < min; i++) {
-			if (PyDict_GetItemString(keywords, kwlist[i]))
-				len++;
-			else if (PyErr_Occurred())
-				return 0;
-		}
-	}
+	/* scan kwlist and get greatest possible nbr of args */
+	for (len=0; kwlist[len]; len++)
+		continue;
 
-	/* make sure we got an acceptable number of arguments; the message
-	   is a little confusing with keywords since keyword arguments
-	   which are supplied, but don't match the required arguments
-	   are not included in the "%d given" part of the message
-	   XXX and this isn't a bug!? */
-	if (len < min || max < len) {
-		if (message == NULL) {
-			PyOS_snprintf(msgbuf, sizeof(msgbuf),
-				      "%.200s%s takes %s %d argument%s "
-				      "(%d given)",
-				      fname==NULL ? "function" : fname,
-				      fname==NULL ? "" : "()",
-				      min==max ? "exactly"
-			              : len < min ? "at least" : "at most",
-				      len < min ? min : max,
-				      (len < min ? min : max) == 1 ? "" : "s",
-				      len);
-			message = msgbuf;
-		}
-		PyErr_SetString(PyExc_TypeError, message);
+	nargs = PyTuple_GET_SIZE(args);
+	nkeywords = (keywords == NULL) ? 0 : PyDict_Size(keywords);
+	if (nargs + nkeywords > len) {
+		PyErr_Format(PyExc_TypeError, "%s%s takes at most %d "
+			     "argument%s (%d given)",
+			     (fname == NULL) ? "function" : fname,
+			     (fname == NULL) ? "" : "()",
+			     len,
+			     (len == 1) ? "" : "s",
+			     nargs + nkeywords);
 		return 0;
 	}
 
-	/* convert the positional arguments */
-	for (i = 0; i < nargs; i++) {
-		if (*format == '|')
+	/* convert tuple args and keyword args in same loop, using kwlist to drive process */
+	for (i = 0; i < len; i++) {
+		keyword = kwlist[i];
+		if (*format == '|') {
+			min = i;
 			format++;
-		msg = convertitem(PyTuple_GET_ITEM(args, i), &format, p_va,
-				  flags, levels, msgbuf, sizeof(msgbuf),
-				  &freelist);
-		if (msg) {
-			seterror(i+1, msg, levels, fname, message);
+		}
+		if (IS_END_OF_FORMAT(*format)) {
+			PyErr_Format(PyExc_RuntimeError,
+				     "More keyword list entries (%d) than "
+				     "format specifiers (%d)", len, i);
 			return cleanreturn(0, freelist);
 		}
-	}
-
-	/* handle no keyword parameters in call */
-	if (nkeywords == 0)
-		return cleanreturn(1, freelist);
-
-	/* convert the keyword arguments; this uses the format
-	   string where it was left after processing args */
-	for (i = nargs; i < max; i++) {
-		PyObject *item;
-		if (*format == '|')
-			format++;
-		item = PyDict_GetItemString(keywords, kwlist[i]);
-		if (item != NULL) {
-			Py_INCREF(item);
-			msg = convertitem(item, &format, p_va, flags, levels,
-					  msgbuf, sizeof(msgbuf), &freelist);
-			Py_DECREF(item);
-			if (msg) {
-				seterror(i+1, msg, levels, fname, message);
+		current_arg = NULL;
+		if (nkeywords) {
+			current_arg = PyDict_GetItemString(keywords, keyword);
+		}
+		if (current_arg) {
+			--nkeywords;
+			if (i < nargs) {
+				/* arg present in tuple and in dict */
+				PyErr_Format(PyExc_TypeError,
+					     "Argument given by name ('%s') "
+					     "and position (%d)",
+					     keyword, i+1);
 				return cleanreturn(0, freelist);
 			}
-			--nkeywords;
-			if (nkeywords == 0)
-				break;
 		}
-		else if (PyErr_Occurred())
+		else if (nkeywords && PyErr_Occurred())
 			return cleanreturn(0, freelist);
-		else {
-			msg = skipitem(&format, p_va, flags);
+		else if (i < nargs)
+			current_arg = PyTuple_GET_ITEM(args, i);
+			
+		if (current_arg) {
+			msg = convertitem(current_arg, &format, p_va, flags,
+				levels, msgbuf, sizeof(msgbuf), &freelist);
 			if (msg) {
-				levels[0] = 0;
-				seterror(i+1, msg, levels, fname, message);
+				seterror(i+1, msg, levels, fname, custom_msg);
 				return cleanreturn(0, freelist);
 			}
+			continue;
+		}
+
+		if (i < min) {
+			PyErr_Format(PyExc_TypeError, "Required argument "
+				     "'%s' (pos %d) not found",
+				     keyword, i+1);
+			return cleanreturn(0, freelist);
+		}
+		/* current code reports success when all required args
+		 * fulfilled and no keyword args left, with no further
+		 * validation. XXX Maybe skip this in debug build ?
+		 */
+		if (!nkeywords)
+			return cleanreturn(1, freelist);
+
+		/* We are into optional args, skip thru to any remaining
+		 * keyword args */
+		msg = skipitem(&format, p_va, flags);
+		if (msg) {
+			PyErr_Format(PyExc_RuntimeError, "%s: '%s'", msg,
+				     format);
+			return cleanreturn(0, freelist);
 		}
 	}
 
+	if (!IS_END_OF_FORMAT(*format)) {
+		PyErr_Format(PyExc_RuntimeError,
+			"more argument specifiers than keyword list entries "
+			"(remaining format:'%s')", format);
+		return cleanreturn(0, freelist);
+	}
+
 	/* make sure there are no extraneous keyword arguments */
 	if (nkeywords > 0) {
 		PyObject *key, *value;
@@ -1597,7 +1535,7 @@ vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
 				return cleanreturn(0, freelist);
 			}
 			ks = PyUnicode_AsString(key);
-			for (i = 0; i < max; i++) {
+			for (i = 0; i < len; i++) {
 				if (!strcmp(ks, kwlist[i])) {
 					match = 1;
 					break;
@@ -1620,7 +1558,7 @@ vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
 static char *
 skipitem(const char **p_format, va_list *p_va, int flags)
 {
-        const char *format = *p_format;
+	const char *format = *p_format;
 	char c = *format++;
 
 	switch (c) {
@@ -1726,15 +1664,32 @@ skipitem(const char **p_format, va_list *p_va, int flags)
 			break;
 		}
 
+	case '(':	/* bypass tuple, not handled at all previously */
+		{
+			char *msg;
+			for (;;) {
+				if (*format==')')
+					break;
+				if (IS_END_OF_FORMAT(*format))
+					return "Unmatched left paren in format "
+					       "string";
+				msg = skipitem(&format, p_va, flags);
+				if (msg)
+					return msg;
+			}
+			format++;
+			break;
+		}
+
+	case ')':
+		return "Unmatched right paren in format string";
+
 	default:
 err:
 		return "impossible<bad format char>";
 
 	}
 
-	/* The "(...)" format code for tuples is not handled here because
-	 * it is not allowed with keyword args. */
-
 	*p_format = format;
 	return NULL;
 }