Backport 1.19:

   Use 'predicate = bool' as the default predicate for ifilter[false].

diff --git a/Doc/lib/libitertools.tex b/Doc/lib/libitertools.tex
index dc1a77c39c8c2082f59c1dcfdb076ccb26c37e7b..596406f176de7300b64669f1bd93af18700000bf 100644 (file)
--- a/Doc/lib/libitertools.tex
+++ b/Doc/lib/libitertools.tex
@@ -140,8 +140,7 @@ by functions or loops that truncate the stream.
   \begin{verbatim}
      def ifilter(predicate, iterable):
          if predicate is None:
-             def predicate(x):
-                 return x
+             predicate = bool
          for x in iterable:
              if predicate(x):
                  yield x
@@ -157,8 +156,7 @@ by functions or loops that truncate the stream.
   \begin{verbatim}
      def ifilterfalse(predicate, iterable):
          if predicate is None:
-             def predicate(x):
-                 return x
+             predicate = bool
          for x in iterable:
              if not predicate(x):
                  yield x