Index: src/org/python/core/PyString.java
===================================================================
--- src/org/python/core/PyString.java	(revision 4809)
+++ src/org/python/core/PyString.java	(working copy)
@@ -2186,6 +2186,93 @@
         }
         return super.unsupportedopMessage(op, o2);
     }
+
+    public PyList rsplit(){
+    	return str_rsplit(null,-1);
+    }
+
+    public PyList rsplit(String sep) {
+        return str_rsplit(sep, -1);
+    }
+
+    public PyList rsplit(String sep, int maxsplit) {
+        return str_rsplit(sep, maxsplit);
+    }
+
+    @ExposedMethod(defaults = {"null", "-1"})
+    final PyList str_rsplit(String sep, int maxsplit) {
+        if (sep != null) {
+            if (sep.length() == 0) {
+                throw Py.ValueError("empty separator");
+            }
+            PyList list = rsplitfields(sep,maxsplit);
+            list.reverse();
+            return list;
+        }
+        PyList list = new PyList();
+        char[] chars = string.toCharArray();
+        if (maxsplit < 0)
+            maxsplit = chars.length;
+
+        int splits = 0;
+        int i = chars.length - 1;
+        while (i > 0 && splits < maxsplit){
+            while(i > 0 && Character.isWhitespace(chars[i]))
+                i--;
+
+            int next_ws_char = i;
+            while (next_ws_char > -1 && !Character.isWhitespace(chars[next_ws_char]))
+        	next_ws_char--;
+            if (next_ws_char == -1)
+                break;
+            splits++;
+            list.add(fromSubstring(next_ws_char+1,i+1));
+            i = next_ws_char;
+        }
+
+        while(i > -1 && Character.isWhitespace(chars[i]))
+    	    i--;
+        if (i > -1)
+            list.add(fromSubstring(0,i+1));
+        //It'd be nice if lists supported a push() method.
+        // Can't use list.insert(0,foo) because a quadratic time would result.
+        list.reverse();
+        return list;
+    }
+    private PyList rsplitfields(String sep, int maxsplit) {
+        PyList list = new PyList();
+
+        int length = string.length();
+        if (maxsplit < 0)
+            maxsplit = length + 1;
+
+        int lastbreak = length;
+        int splits = 0;
+        int index = length;
+        int sepLength = sep.length();
+
+
+        if ((sep.length() == 0) && (maxsplit != 0)) {
+            index = string.lastIndexOf(sep, lastbreak);
+            list.append(fromSubstring(index /* +sepLength (= 0)*/, lastbreak));
+            splits++;
+        }
+
+        while (splits < maxsplit) {
+            index = string.lastIndexOf(sep, index-1);
+            if (index == -1)
+                break;
+            if (sep.length() == 0)
+                index++;
+            splits++;
+            list.append(fromSubstring(index+sepLength, lastbreak));
+            lastbreak = index;
+        }
+        if (lastbreak > -1) {
+            list.append(fromSubstring(0, lastbreak));
+        }
+        return list;
+    }
 }
 
 final class StringFormatter
Index: Lib/test/string_tests.py
===================================================================
--- Lib/test/string_tests.py	(revision 4809)
+++ Lib/test/string_tests.py	(working copy)
@@ -185,9 +185,21 @@
         self.checkequal(['a', 'b', 'c  d'], 'a  b  c  d', 'split', None, 2)
         self.checkequal(['a', 'b', 'c', 'd'], 'a b c d ', 'split')
         self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'split', '//')
-        #self.checkequal(['endcase ', ''], 'endcase test', 'split', 'test')
-
+        #rsplit
+        self.checkequal(['a', 'b', 'c', 'd'], 'a|b|c|d', 'rsplit', '|')
+        self.checkequal(['a|b', 'c','d'], 'a|b|c|d', 'rsplit', '|', 2)
+        self.checkequal(['a b c', 'd'], 'a b c d', 'rsplit', None, 1)
+        self.checkequal(['a b', 'c', 'd'], 'a b c d', 'rsplit', None, 2)
+        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'rsplit', None, 3)
+        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d', 'rsplit', None, 4)
+        self.checkequal(['a b c d'], 'a b c d', 'split', None, 0)
+        self.checkequal(['a  b', 'c','d'], 'a  b  c  d', 'rsplit', None, 2)
+        self.checkequal(['a', 'b', 'c', 'd'], 'a b c d ', 'rsplit')
+        self.checkequal(['a', 'b', 'c', 'd'], 'a//b//c//d', 'rsplit', '//')
+        self.checkequal(['','foo','bar','baz'], '/foo/bar/baz', 'rsplit', "/")
         self.checkraises(TypeError, 'hello', 'split', 42, 42, 42)
+        self.checkraises(ValueError, 'hello', 'rsplit', "",42)
+        self.checkraises(ValueError, 'hello', 'rsplit', "")
 
     def test_strip(self):
         self.checkequal('hello', '   hello   ', 'strip')