[Python-checkins] r59907 - python/trunk/Lib/difflib.py

[raymond.hettinger]

Author: raymond.hettinger
Date: Fri Jan 11 04:20:54 2008
New Revision: 59907

Modified:
   python/trunk/Lib/difflib.py
Log:
Improve usability of the SequenceMatcher by returning named tuples describing match ranges.

Modified: python/trunk/Lib/difflib.py
==============================================================================
--- python/trunk/Lib/difflib.py	(original)
+++ python/trunk/Lib/difflib.py	Fri Jan 11 04:20:54 2008
@@ -30,9 +30,12 @@
 
 __all__ = ['get_close_matches', 'ndiff', 'restore', 'SequenceMatcher',
            'Differ','IS_CHARACTER_JUNK', 'IS_LINE_JUNK', 'context_diff',
-           'unified_diff', 'HtmlDiff']
+           'unified_diff', 'HtmlDiff', 'Match']
 
 import heapq
+from collections import namedtuple as _namedtuple
+
+Match = _namedtuple('Match', 'a b size')
 
 def _calculate_ratio(matches, length):
     if length:
@@ -363,7 +366,7 @@
 
         >>> s = SequenceMatcher(None, " abcd", "abcd abcd")
         >>> s.find_longest_match(0, 5, 0, 9)
-        (0, 4, 5)
+        Match(a=0, b=4, size=5)
 
         If isjunk is defined, first the longest matching block is
         determined as above, but with the additional restriction that no
@@ -379,13 +382,13 @@
 
         >>> s = SequenceMatcher(lambda x: x==" ", " abcd", "abcd abcd")
         >>> s.find_longest_match(0, 5, 0, 9)
-        (1, 0, 4)
+        Match(a=1, b=0, size=4)
 
         If no blocks match, return (alo, blo, 0).
 
         >>> s = SequenceMatcher(None, "ab", "c")
         >>> s.find_longest_match(0, 2, 0, 1)
-        (0, 0, 0)
+        Match(a=0, b=0, size=0)
         """
 
         # CAUTION:  stripping common prefix or suffix would be incorrect.
@@ -452,7 +455,7 @@
               a[besti+bestsize] == b[bestj+bestsize]:
             bestsize = bestsize + 1
 
-        return besti, bestj, bestsize
+        return Match(besti, bestj, bestsize)
 
     def get_matching_blocks(self):
         """Return list of triples describing matching subsequences.
@@ -470,7 +473,7 @@
 
         >>> s = SequenceMatcher(None, "abxcd", "abcd")
         >>> s.get_matching_blocks()
-        [(0, 0, 2), (3, 2, 2), (5, 4, 0)]
+        [Match(a=0, b=0, size=2), Match(a=3, b=2, size=2), Match(a=5, b=4, size=0)]
         """
 
         if self.matching_blocks is not None:
@@ -523,7 +526,7 @@
 
         non_adjacent.append( (la, lb, 0) )
         self.matching_blocks = non_adjacent
-        return self.matching_blocks
+        return map(Match._make, self.matching_blocks)
 
     def get_opcodes(self):
         """Return list of 5-tuples describing how to turn a into b.