Index: PythonSourceLibs/sre_constants.py
===================================================================
--- PythonSourceLibs/sre_constants.py	(revision 62045)
+++ PythonSourceLibs/sre_constants.py	(working copy)
@@ -54,6 +54,7 @@
 MAX_UNTIL = "max_until"
 MIN_REPEAT = "min_repeat"
 MIN_UNTIL = "min_until"
+POSSESSIVE_REPEAT = "possessive_repeat"
 NEGATE = "negate"
 NOT_LITERAL = "not_literal"
 NOT_LITERAL_IGNORE = "not_literal_ignore"
@@ -61,6 +62,7 @@
 REPEAT = "repeat"
 REPEAT_ONE = "repeat_one"
 SUBPATTERN = "subpattern"
+ATOMIC_GROUP = "atomic_group"
 MIN_REPEAT_ONE = "min_repeat_one"
 
 # positions
@@ -97,6 +99,10 @@
 CATEGORY_UNI_LINEBREAK = "category_uni_linebreak"
 CATEGORY_UNI_NOT_LINEBREAK = "category_uni_not_linebreak"
 
+SRE_GROUP_IGNORE = "ignore_this_group"
+SRE_GROUP_CAPTURE = "capture_this_group"
+SRE_GROUP_NON_CAPTURE = "non_capturing_group"
+
 OPCODES = [
 
     # failure=0 success=1 (just because it looks better that way :-)
Index: PythonSourceLibs/sre_parse.py
===================================================================
--- PythonSourceLibs/sre_parse.py	(revision 62045)
+++ PythonSourceLibs/sre_parse.py	(working copy)
@@ -424,8 +424,6 @@
             # character set
             set = []
             setappend = set.append
-##          if sourcematch(":"):
-##              pass # handle character classes
             if sourcematch("^"):
                 setappend((NEGATE, None))
             # check remaining characters
@@ -522,19 +520,25 @@
             if item[0][0] in REPEATCODES:
                 raise error, "multiple repeat"
             if sourcematch("?"):
+                # Non-Greedy Match
                 subpattern[-1] = (MIN_REPEAT, (min, max, item))
+            elif sourcematch("+"):
+                # Possessive Match (Always Greedy)
+                subpattern[-1] = (POSSESSIVE_REPEAT, (min, max, item))
             else:
+                # Greedy Match
                 subpattern[-1] = (MAX_REPEAT, (min, max, item))
 
         elif this == ".":
             subpatternappend((ANY, None))
 
         elif this == "(":
-            group = 1
+            grouptype = SRE_GROUP_CAPTURE
             name = None
             condgroup = None
+            atomic = False
             if sourcematch("?"):
-                group = 0
+                grouptype = SRE_GROUP_IGNORE
                 # options
                 if sourcematch("P"):
                     # python extensions
@@ -548,7 +552,7 @@
                             if char == ">":
                                 break
                             name = name + char
-                        group = 1
+                        grouptype = SRE_GROUP_CAPTURE
                         if not isname(name):
                             raise error, "bad character in group name"
                     elif sourcematch("="):
@@ -568,6 +572,27 @@
                             raise error, "unknown group name"
                         subpatternappend((GROUPREF, gid))
                         continue
+                    elif sourcematch("#"):
+                        # Python-Specific Comment -- allows for nested
+                        # paren
+                        depth = 1
+                        while 1:
+                            if sourcematch("\\"):
+                                # Ignore escaped characters
+                                if not source.next:
+                                    break
+                            elif source.next == "(":
+                                depth += 1
+                            elif source.next == ")":
+                                depth -= 1
+                                if not depth:
+                                    break
+                            if source.next is None:
+                                break
+                            sourceget()
+                        if not sourcematch(")"):
+                            raise error, "unbalanced parenthesis"
+                        continue
                     else:
                         char = sourceget()
                         if char is None:
@@ -575,7 +600,7 @@
                         raise error, "unknown specifier: ?P%s" % char
                 elif sourcematch(":"):
                     # non-capturing group
-                    group = 2
+                    grouptype = SRE_GROUP_NON_CAPTURE
                 elif sourcematch("#"):
                     # comment
                     while 1:
@@ -612,7 +637,7 @@
                         if char == ")":
                             break
                         condname = condname + char
-                    group = 2
+                    grouptype = SRE_GROUP_NON_CAPTURE
                     if isname(condname):
                         condgroup = state.groupdict.get(condname)
                         if condgroup is None:
@@ -622,15 +647,19 @@
                             condgroup = int(condname)
                         except ValueError:
                             raise error, "bad character in group name"
+                elif sourcematch(">"):
+                    # non-capturing, atomic group
+                    grouptype = SRE_GROUP_NON_CAPTURE
+                    atomic = True
                 else:
                     # flags
                     if not source.next in FLAGS:
                         raise error, "unexpected end of pattern"
                     while source.next in FLAGS:
                         state.flags = state.flags | FLAGS[sourceget()]
-            if group:
+            if grouptype != SRE_GROUP_IGNORE:
                 # parse group contents
-                if group == 2:
+                if grouptype == SRE_GROUP_NON_CAPTURE:
                     # anonymous group
                     group = None
                 else:
@@ -643,7 +672,10 @@
                     raise error, "unbalanced parenthesis"
                 if group is not None:
                     state.closegroup(group)
-                subpatternappend((SUBPATTERN, (group, p)))
+                if atomic:
+                    subpatternappend((ATOMIC_GROUP, (group, p)))
+                else:
+                    subpatternappend((SUBPATTERN, (group, p)))
             else:
                 while 1:
                     char = sourceget()