itertools, operator and functools are not really "numeric" modules; move them into their own "functional" chapter.
diff --git a/Doc/library/index.rst b/Doc/library/index.rst
index 39e0c20..9ac688c 100644
--- a/Doc/library/index.rst
+++ b/Doc/library/index.rst
@@ -49,6 +49,7 @@
    strings.rst
    datatypes.rst
    numeric.rst
+   functional.rst
    filesys.rst
    persistence.rst
    archiving.rst