Issue1023

str.rsplit was added in 2.4. This should be a pretty straightforward 
job, basically copy the existing split methods (there's two, one for a 
split char and one for whitespace) but start from the end.
With this and partition/rpartition str will be up to speed for 2.5, and 
there's already a patch for those 2: #1797751 

Hi, I have made a simple implementation of rsplit for PyString in these 
two diffs. Unicode seems to have it already. I have some tests, but not 
enough. Some tests from CPython will probably have to be included as 
well, but I couldn't find any.

There's a bunch of rsplit tests in CPython 2.5's string_tests (which is 
used by test_str and test_unicode). The asm branch has the 2.5 stdlib now 
in the CPythonLib/ dir

Ok, here is an updated patch with all those tests. When I run regrtest, 
I get 4 failures- test_atexit,test_cpickle,test_re and test_socket, but 
test_string works fine.

Also, I'm not sure whether CPythonLib/string.py should be patched to 
include rstrip, but I had to get test_string to work. Here is what I 
did.

applied to the asm branch in r4893. I also updated the string_tests to 
2.5 which should include the new rsplit tests from the stdlib
I fixed the patch to adhere to our coding standards (no tabs, fixed 
whitespace, camel case java vars)
I also removed the comment about having to use list reverse instead of a 
push because apparently CPython does the exact same thing (list.reverse) 
in this case
Thanks Nimish!

reopening to remind ourselves we need unicode rsplit. this'll use the same 
str rsplit code unless it's not a basic plane unicode string -- then, it 
needs something else

PyUnicode#rsplit calls PyString#rsplit (no need to be aware of UTF-16 
encoding issues)