From 85cb20d0f7582e29140708e84c86876b56cc21aa Mon Sep 17 00:00:00 2001
From: unutbu <unutbu@gmail.com>
Date: Mon, 21 Apr 2014 17:24:04 -0400
Subject: [PATCH] DOC: Add recipe for shifting groups of values based on the
 index

---
 doc/source/cookbook.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/doc/source/cookbook.rst b/doc/source/cookbook.rst
index 41a270a37d187..5f0b65218d374 100644
--- a/doc/source/cookbook.rst
+++ b/doc/source/cookbook.rst
@@ -191,6 +191,19 @@ The :ref:`grouping <groupby>` docs.
 `Create a value counts column and reassign back to the DataFrame
 <http://stackoverflow.com/questions/17709270/i-want-to-create-a-column-of-value-counts-in-my-pandas-dataframe>`__
 
+`Shift groups of the values in a column based on the index
+<http://stackoverflow.com/q/23198053/190597>`__
+
+.. ipython:: python
+
+   df = pd.DataFrame(
+        {u'line_race': [10L, 10L, 8L, 10L, 10L, 8L],
+         u'beyer': [99L, 102L, 103L, 103L, 88L, 100L]},
+        index=[u'Last Gunfighter', u'Last Gunfighter', u'Last Gunfighter',
+               u'Paynter', u'Paynter', u'Paynter']); df
+   
+   df['beyer_shifted'] = df.groupby(level=0)['beyer'].apply(lambda grp: grp.shift(1))
+   df
 
 Expanding Data
 ~~~~~~~~~~~~~~