diff -r 4a48450f2505 Doc/library/itertools.rst
--- a/Doc/library/itertools.rst	Sat Jun 14 20:41:22 2014 -0700
+++ b/Doc/library/itertools.rst	Sun Jun 15 15:55:14 2014 +0200
@@ -52,7 +52,7 @@
 :func:`compress`                data, selectors                 (d[0] if s[0]), (d[1] if s[1]), ...                 ``compress('ABCDEF', [1,0,1,0,1,1]) --> A C E F``
 :func:`dropwhile`               pred, seq                       seq[n], seq[n+1], starting when pred fails          ``dropwhile(lambda x: x<5, [1,4,6,4,1]) --> 6 4 1``
 :func:`filterfalse`             pred, seq                       elements of seq where pred(elem) is false           ``filterfalse(lambda x: x%2, range(10)) --> 0 2 4 6 8``
-:func:`groupby`                 iterable[, keyfunc]             sub-iterators grouped by value of keyfunc(v)
+:func:`groupby`                 iterable[, key]                 sub-iterators grouped by value of key(v)
 :func:`islice`                  seq, [start,] stop [, step]     elements from seq[start:stop:step]                  ``islice('ABCDEFG', 2, None) --> C D E F G``
 :func:`starmap`                 func, seq                       func(\*seq[0]), func(\*seq[1]), ...                 ``starmap(pow, [(2,5), (3,2), (10,3)]) --> 32 9 1000``
 :func:`takewhile`               pred, seq                       seq[0], seq[1], until pred fails                    ``takewhile(lambda x: x<5, [1,4,6,4,1]) --> 1 4``
diff -r 4a48450f2505 Modules/itertoolsmodule.c
--- a/Modules/itertoolsmodule.c	Sat Jun 14 20:41:22 2014 -0700
+++ b/Modules/itertoolsmodule.c	Sun Jun 15 15:55:14 2014 +0200
@@ -182,7 +182,7 @@
 };
 
 PyDoc_STRVAR(groupby_doc,
-"groupby(iterable[, keyfunc]) -> create an iterator which returns\n\
+"groupby(iterable[, key]) -> create an iterator which returns\n\
 (key, sub-iterator) grouped by each value of key(value).\n");
 
 static PyTypeObject groupby_type = {
@@ -4529,7 +4529,7 @@
 chain.from_iterable([p, q, ...]) --> p0, p1, ... plast, q0, q1, ... \n\
 compress(data, selectors) --> (d[0] if s[0]), (d[1] if s[1]), ...\n\
 dropwhile(pred, seq) --> seq[n], seq[n+1], starting when pred fails\n\
-groupby(iterable[, keyfunc]) --> sub-iterators grouped by value of keyfunc(v)\n\
+groupby(iterable[, key]) --> sub-iterators grouped by value of keyfunc(v)\n\
 filterfalse(pred, seq) --> elements of seq where pred(elem) is False\n\
 islice(seq, [start,] stop [, step]) --> elements from\n\
        seq[start:stop:step]\n\