Forward port r68941 adding itertools.compress().
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 803abab..a8911d6 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -286,7 +286,7 @@
Section 4.6.3, Exercise 19*\.
* To enumerate all distinct multisets of a given size over a given set of
- elements, see the :func:`combinations_with_replacement` function in the
+ elements, see :func:`combinations_with_replacement` in the
:ref:`itertools-recipes` for itertools::
map(Counter, combinations_with_replacement('ABC', 2)) --> AA AB AC BB BC CC
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 36254cd..d281278 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -133,6 +133,20 @@
The number of items returned is ``n! / r! / (n-r)!`` when ``0 <= r <= n``
or zero when ``r > n``.
+.. function:: compress(data, selectors)
+
+ Make an iterator that filters elements from *data* returning only those that
+ have a corresponding element in *selectors* that evaluates to ``True``.
+ Stops when either the *data* or *selectors* iterables have been exhausted.
+ Equivalent to::
+
+ def compress(data, selectors):
+ # compress('ABCDEF', [1,0,1,0,1,1]) --> A C E F
+ return (d for d, s in zip(data, selectors) if s)
+
+ .. versionadded:: 2.7
+
+
.. function:: count([n])
Make an iterator that returns consecutive integers starting with *n*. If not
@@ -594,10 +608,6 @@
s = list(iterable)
return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))
- def compress(data, selectors):
- "compress('ABCDEF', [1,0,1,0,1,1]) --> A C E F"
- return (d for d, s in zip(data, selectors) if s)
-
def combinations_with_replacement(iterable, r):
"combinations_with_replacement('ABC', 2) --> AA AB AC BB BC CC"
# number items returned: (n+r-1)! / r! / (n-1)!