Fred, THIS NEEDS DOCS! The function docstrings tell the tale.

Christmas present to myself:  the bisect module didn't define what
happened if the new element was already in the list.  It so happens
that it inserted the new element "to the right" of all equal elements.
Since it wasn't defined, among other bad implications it was a mystery
how to use bisect to determine whether an element was already in the
list (I've seen code that *assumed* "to the right" without justification).
Added new methods bisect_left and insort_left that insert "to the left"
instead; made the old names bisect and insort aliases for the new names
bisect_right and insort_right; beefed up docstrings to explain what
these actually do; and added a std test for the bisect module.

1 files changed, 12 insertions, 0 deletions

diff --git a/Misc/NEWS b/Misc/NEWS
index df81a12..8f66106 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -34,6 +34,18 @@ Core language, builtins, and interpreter
   item.  Such algorithms normally end up running in quadratic time;
   using popitem() they can usually be made to run in linear time.
 
+
+Standard library
+
+- The bisect module has new functions bisect_left, insort_left,
+  bisect_right and insort_right.  The old names bisect and insort
+  are now aliases for bisect_right and insort_right.  XXX_right
+  and XXX_left methods differ in what happens when the new element
+  compares equal to one or more elements already in the list:  the
+  XXX_left methods insert to the left, the XXX_right methods to the
+  right.
+
+
 Windows changes
 
 - select module:  By default under Windows, a select() call