Fix for problem with Sniffer class. If your delimiter is whitespace and the

last field was empty it would strip the delimiter and incorrectly guess that
"" was the delimiter.  Reported in c.l.py by Laurent Laporte.  Will
backport.

Lib/csv.py

@@ -271,7 +271,7 @@ def _guess_delimiter(self, data, delimiters):
                 for char in ascii:
                     metaFrequency = charFrequency.get(char, {})
                     # must count even if frequency is 0
-                    freq = line.strip().count(char)
+                    freq = line.count(char)
                     # value is the mode
                     metaFrequency[freq] = metaFrequency.get(freq, 0) + 1
                     charFrequency[char] = metaFrequency

Lib/test/test_csv.py

@@ -836,7 +836,6 @@ class TestSniffer(unittest.TestCase):
 'Tommy''s Place':'Blue Island':'IL':'12/28/02':'Blue Sunday/White Crow'
 'Stonecutters Seafood and Chop House':'Lemont':'IL':'12/19/02':'Week Back'
 """
-
     header = '''\
 "venue","city","state","date","performers"
 '''
@@ -852,6 +851,8 @@ class TestSniffer(unittest.TestCase):
 47483648;43.0;170;abc;def
 '''
 
+    sample5 = "aaa\tbbb\r\nAAA\t\r\nBBB\t\r\n"
+
     def test_has_header(self):
         sniffer = csv.Sniffer()
         self.assertEqual(sniffer.has_header(self.sample1), False)
@@ -879,6 +880,8 @@ def test_delimiters(self):
         self.assertEqual(dialect.delimiter, "/")
         dialect = sniffer.sniff(self.sample4)
         self.assertEqual(dialect.delimiter, ";")
+        dialect = sniffer.sniff(self.sample5)
+        self.assertEqual(dialect.delimiter, "\t")
 
 if not hasattr(sys, "gettotalrefcount"):
     if test_support.verbose: print "*** skipping leakage tests ***"