Move itertools module from the sandbox and into production.

Doc/lib/lib.tex

@@ -125,6 +125,7 @@ and how to embed it in other applications.
 \input{libheapq}
 \input{libarray}
 \input{libsets}
+\input{libitertools}
 \input{libcfgparser}
 \input{libfileinput}
 \input{libxreadlines}

Lib/test/test_itertools.py

+import unittest
+from test import test_support
+from itertools import *
+
+class TestBasicOps(unittest.TestCase):
+    def test_count(self):
+        self.assertEqual(zip('abc',count()), [('a', 0), ('b', 1), ('c', 2)])
+        self.assertEqual(zip('abc',count(3)), [('a', 3), ('b', 4), ('c', 5)])
+        self.assertRaises(TypeError, count, 2, 3)
+
+    def test_ifilter(self):
+        def isEven(x):
+            return x%2==0
+        self.assertEqual(list(ifilter(isEven, range(6))), [0,2,4])
+        self.assertEqual(list(ifilter(isEven, range(6), True)), [1,3,5])
+        self.assertEqual(list(ifilter(None, [0,1,0,2,0])), [1,2])
+        self.assertRaises(TypeError, ifilter)
+        self.assertRaises(TypeError, ifilter, 3)
+        self.assertRaises(TypeError, ifilter, isEven, 3)
+        self.assertRaises(TypeError, ifilter, isEven, [3], True, 4)
+
+    def test_izip(self):
+        ans = [(x,y) for x, y in izip('abc',count())]
+        self.assertEqual(ans, [('a', 0), ('b', 1), ('c', 2)])
+        self.assertRaises(TypeError, izip)
+
+    def test_repeat(self):
+        self.assertEqual(zip(xrange(3),repeat('a')),
+                         [(0, 'a'), (1, 'a'), (2, 'a')])
+        self.assertRaises(TypeError, repeat)
+
+    def test_times(self):
+        self.assertEqual(list(times(3)), [None]*3)
+        self.assertEqual(list(times(3, True)), [True]*3)
+        self.assertRaises(ValueError, times, -1)
+
+    def test_imap(self):
+        import operator
+        self.assertEqual(list(imap(operator.pow, range(3), range(1,7))),
+                         [0**1, 1**2, 2**3])
+        self.assertEqual(list(imap(None, 'abc', range(5))),
+                         [('a',0),('b',1),('c',2)])
+        self.assertRaises(TypeError, imap)
+        self.assertRaises(TypeError, imap, operator.neg)
+
+    def test_starmap(self):
+        import operator
+        self.assertEqual(list(starmap(operator.pow, zip(range(3), range(1,7)))),
+                         [0**1, 1**2, 2**3])
+
+    def test_islice(self):
+        for args in [          # islice(args) should agree with range(args)
+                (10, 20, 3),
+                (10, 3, 20),
+                (10, 20),
+                (10, 3),
+                (20,)
+                ]:
+            self.assertEqual(list(islice(xrange(100), *args)), range(*args))
+
+        for args, tgtargs in [  # Stop when seqn is exhausted
+                ((10, 110, 3), ((10, 100, 3))),
+                ((10, 110), ((10, 100))),
+                ((110,), (100,))
+                ]:
+            self.assertEqual(list(islice(xrange(100), *args)), range(*tgtargs))
+
+        self.assertRaises(TypeError, islice, xrange(10))
+        self.assertRaises(TypeError, islice, xrange(10), 1, 2, 3, 4)
+        self.assertRaises(ValueError, islice, xrange(10), -5, 10, 1)
+        self.assertRaises(ValueError, islice, xrange(10), 1, -5, -1)
+        self.assertRaises(ValueError, islice, xrange(10), 1, 10, -1)
+        self.assertRaises(ValueError, islice, xrange(10), 1, 10, 0)
+
+    def test_takewhile(self):
+        data = [1, 3, 5, 20, 2, 4, 6, 8]
+        underten = lambda x: x<10
+        self.assertEqual(list(takewhile(underten, data)), [1, 3, 5])
+
+    def test_dropwhile(self):
+        data = [1, 3, 5, 20, 2, 4, 6, 8]
+        underten = lambda x: x<10
+        self.assertEqual(list(dropwhile(underten, data)), [20, 2, 4, 6, 8])
+
+libreftest = """ Doctest for examples in the library reference, libitertools.tex
+
+>>> for i in times(3):
+...     print "Hello"
+...
+Hello
+Hello
+Hello
+
+>>> amounts = [120.15, 764.05, 823.14]
+>>> for checknum, amount in izip(count(1200), amounts):
+...     print 'Check %d is for $%.2f' % (checknum, amount)
+...
+Check 1200 is for $120.15
+Check 1201 is for $764.05
+Check 1202 is for $823.14
+
+>>> import operator
+>>> import operator
+>>> for cube in imap(operator.pow, xrange(1,4), repeat(3)):
+...    print cube
+...
+1
+8
+27
+
+>>> reportlines = ['EuroPython', 'Roster', '', 'alex', '', 'laura', '', 'martin', '', 'walter', '', 'samuele']
+>>> for name in islice(reportlines, 3, len(reportlines), 2):
+...    print name.title()
+...
+Alex
+Laura
+Martin
+Walter
+Samuele
+
+>>> def enumerate(iterable):
+...     return izip(count(), iterable)
+
+>>> def tabulate(function):
+...     "Return function(0), function(1), ..."
+...     return imap(function, count())
+
+>>> def iteritems(mapping):
+...     return izip(mapping.iterkeys(), mapping.itervalues())
+
+>>> def nth(iterable, n):
+...     "Returns the nth item"
+...     return islice(iterable, n, n+1).next()
+
+"""
+
+__test__ = {'libreftest' : libreftest}
+
+def test_main(verbose=None):
+    import test_itertools
+    suite = unittest.TestSuite()
+    for testclass in (TestBasicOps,
+                          ):
+        suite.addTest(unittest.makeSuite(testclass))
+    test_support.run_suite(suite)
+    test_support.run_doctest(test_itertools, verbose)
+
+    # verify reference counting
+    import sys
+    if verbose and hasattr(sys, "gettotalrefcount"):
+        counts = []
+        for i in xrange(5):
+            test_support.run_suite(suite)
+            counts.append(sys.gettotalrefcount())
+        print counts
+
+if __name__ == "__main__":
+    test_main(verbose=True)

Misc/NEWS

@@ -30,6 +30,9 @@ Core and builtins
 Extension modules
 -----------------
 
+- Added an itertools module containing high speed, memory efficient
+  looping constructs inspired by tools from Haskell and SML.
+
 - The SSL module now handles sockets with a timeout set correctly (SF
   patch #675750, fixing SF bug #675552).
 

PC/config.c

@@ -45,6 +45,7 @@ extern void init_hotshot(void);
 extern void initxxsubtype(void);
 extern void initzipimport(void);
 extern void init_random(void);
+extern void inititertools(void);
 
 /* XXX tim: what's the purpose of ADDMODULE MARKER? */
 /* -- ADDMODULE MARKER 1 -- */
@@ -97,6 +98,7 @@ struct _inittab _PyImport_Inittab[] = {
 	{"_weakref", init_weakref},
 	{"_hotshot", init_hotshot},
 	{"_random", init_random},
+	{"itertools", inititertools},
 
 	{"xxsubtype", initxxsubtype},
 	{"zipimport", initzipimport},

PCbuild/pythoncore.dsp

@@ -323,6 +323,10 @@ SOURCE=..\Objects\iterobject.c
 # End Source File
 # Begin Source File
 
+SOURCE=..\Modules\itertoolsmodule.c
+# End Source File
+# Begin Source File
+
 SOURCE=..\Parser\listnode.c
 # End Source File
 # Begin Source File

setup.py

@@ -324,6 +324,8 @@ class PyBuildExt(build_ext):
                                libraries=math_libs) )
         # random number generator implemented in C
         exts.append( Extension("_random", ["_randommodule.c"]) )
+        # fast iterator tools implemented in C
+        exts.append( Extension("itertools", ["itertoolsmodule.c"]) )
         # operator.add() and similar goodies
         exts.append( Extension('operator', ['operator.c']) )
         # Python C API test module