Merged revisions 61038,61042-61045,61047,61050,61053,61055-61056,61061-61062,61066,61068,61070,61083,61085,61092-61103 via svnmerge from

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

........
  r61098 | jeffrey.yasskin | 2008-02-28 05:45:36 +0100 (Thu, 28 Feb 2008) | 7 lines

  Move abc._Abstract into object by adding a new flag Py_TPFLAGS_IS_ABSTRACT,
  which forbids constructing types that have it set. The effect is to speed

    ./python.exe -m timeit -s 'import abc' -s 'class Foo(object): __metaclass__ = abc.ABCMeta' 'Foo()'

  up from 2.5us to 0.201us. This fixes issue 1762.
........
  r61099 | jeffrey.yasskin | 2008-02-28 06:53:18 +0100 (Thu, 28 Feb 2008) | 3 lines

  Speed test_socketserver up from 28.739s to 0.226s, simplify the logic, and make
  sure all tests run even if some fail.
........
  r61100 | jeffrey.yasskin | 2008-02-28 07:09:19 +0100 (Thu, 28 Feb 2008) | 21 lines

  Thread.start() used sleep(0.000001) to make sure it didn't return before the
  new thread had started. At least on my MacBook Pro, that wound up sleeping for
  a full 10ms (probably 1 jiffy). By using an Event instead, we can be absolutely
  certain that the thread has started, and return more quickly (217us).

  Before:
  $  ./python.exe -m timeit -s 'from threading import Thread'  't = Thread(); t.start(); t.join()'
  100 loops, best of 3: 10.3 msec per loop
  $  ./python.exe -m timeit -s 'from threading import Thread; t = Thread()'  't.isAlive()'
  1000000 loops, best of 3: 0.47 usec per loop

  After:
  $  ./python.exe -m timeit -s 'from threading import Thread'  't = Thread(); t.start(); t.join()'
  1000 loops, best of 3: 217 usec per loop
  $  ./python.exe -m timeit -s 'from threading import Thread; t = Thread()'  't.isAlive()'
  1000000 loops, best of 3: 0.86 usec per loop

  To be fair, the 10ms isn't CPU time, and other threads including the spawned
  one get to run during it. There are also some slightly more complicated ways to
  get back the .4us in isAlive() if we want.
........
  r61101 | raymond.hettinger | 2008-02-28 10:23:48 +0100 (Thu, 28 Feb 2008) | 1 line

  Add repeat keyword argument to itertools.product().
........
  r61102 | christian.heimes | 2008-02-28 12:18:49 +0100 (Thu, 28 Feb 2008) | 1 line

  The empty tuple is usually a singleton with a much higher refcnt than 1
........

1 files changed, 7 insertions, 3 deletions

diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 826fa45..73abb89 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -327,7 +327,7 @@ loops that truncate the stream.
    example :func:`islice` or :func:`takewhile`).
 
 
-.. function:: product(*iterables)
+.. function:: product(*iterables[, repeat])
 
    Cartesian product of input iterables.
 
@@ -340,11 +340,15 @@ loops that truncate the stream.
    so that if the inputs iterables are sorted, the product tuples are emitted
    in sorted order.
 
+   To compute the product of an iterable with itself, specify the number of
+   repetitions with the optional *repeat* keyword argument.  For example,
+   ``product(A, repeat=4)`` means the same as ``product(A, A, A, A)``.
+
    Equivalent to the following except that the actual implementation does not
    build-up intermediate results in memory::
 
-       def product(*args):
-           pools = map(tuple, args)
+       def product(*args, **kwds):
+           pools = map(tuple, args) * kwds.get('repeat', 1)
            if pools:            
                result = [[]]
                for pool in pools: