Update documentations for str.rsplit() with Alex Martelli's rewrite.

Doc/lib/libstdtypes.tex

@@ -694,21 +694,11 @@ The original string is returned if
 \versionchanged[Support for the \var{fillchar} argument]{2.4}
 \end{methoddesc}
 
-\begin{methoddesc}[string]{rsplit}{\optional{, sep\optional{, maxsplit}}}
-Return a list of the words of the string, scanning the string from
-the end working forward.  The resulting list of words is in the
-same order as \function{split()}.  If the optional second argument
-\var{sep} is absent or \code{None}, the words are separated by
-arbitrary strings of whitespace characters (space, tab, newline,
-return, formfeed).  If the second argument \var{sep} is present and
-not \code{None}, it specifies a string to be used as the word
-separator.  The returned list will then have one more item than the
-number of non-overlapping occurrences of the separator in the string.
-The optional third argument \var{maxsplit} defaults to 0.  If it
-is nonzero, at most \var{maxsplit} number of splits occur, and the
-remainder of the string is returned as the first element of the
-list (thus, the list will have at most \code{\var{maxsplit}+1}
-elements).
+\begin{methoddesc}[string]{rsplit}{\optional{sep \optional{,maxsplit}}}
+Return a list of the words in the string, using \var{sep} as the
+delimiter string.  If \var{maxsplit} is given, at most \var{maxsplit}
+splits are done, the \em{rightmost} ones.  If \var{sep} is not specified
+or \code{None}, any whitespace string is a separator.
 \versionadded{2.4}
 \end{methoddesc}
 

Doc/lib/libstring.tex

@@ -216,19 +216,14 @@ The functions defined in this module are:
 \end{funcdesc}
 
 \begin{funcdesc}{rsplit}{s\optional{, sep\optional{, maxsplit}}}
-  Return a list of the words of the string \var{s}, scanning \var{s} from
-  the end working forward.  The resulting list of words is in the same
-  order as \function{split()}.  If the optional second argument \var{sep}
-  is absent or \code{None}, the words are separated by arbitrary strings
-  of whitespace characters (space, tab, newline, return, formfeed).
-  If the second argument \var{sep} is present and not \code{None}, it
-  specifies a string to be used as the word separator.  The returned
-  list will then have one more item than the number of non-overlapping
-  occurrences of the separator in the string.  The optional third argument
-  \var{maxsplit} defaults to 0.  If it is nonzero, at most \var{maxsplit}
-  number of splits occur, and the remainder of the string is returned
-  as the first element of the list (thus, the list will have at most
-  \code{\var{maxsplit}+1} elements).
+  Return a list of the words of the string \var{s}, scanning \var{s}
+  from the end.  To all intents and purposes, the resulting list of
+  words is the same as returned by \function{split()}, except when the
+  optional third argument \var{maxsplit} is explicitly specified and
+  nonzero.  When \var{maxsplit} is nonzero, at most \var{maxsplit}
+  number of splits -- the \em{rightmost} ones -- occur, and the remainder
+  of the string is returned as the first element of the list (thus, the
+  list will have at most \code{\var{maxsplit}+1} elements).
   \versionadded{2.4}
 \end{funcdesc}