Change time.strptime() to raise ValueError whenever there is an error in the

format string.  Before exceptions generated by the internal code propagated up
to the user and were not helpful.

Closes bug #1340337.

diff --git a/Lib/_strptime.py b/Lib/_strptime.py
index 08d79603a01688baed19241b8d9b59e0c6d13ec4..ce8525b7169ba39e1e1f981d7ccd738fe947dd57 100644 (file)
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@@ -287,7 +287,20 @@ def strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
             _regex_cache.clear()
         format_regex = _regex_cache.get(format)
         if not format_regex:
-            format_regex = time_re.compile(format)
+            try:
+                format_regex = time_re.compile(format)
+            # KeyError raised when a bad format is found; can be specified as
+            # \\, in which case it was a stray % but with a space after it
+            except KeyError, err:
+                bad_directive = err.args[0]
+                if bad_directive == "\\":
+                    bad_directive = "%"
+                del err
+                raise ValueError("'%s' is a bad directive in format '%s'" %
+                                    (bad_directive, format))
+            # IndexError only occurs when the format string is "%"
+            except IndexError:
+                raise ValueError("stray %% in format '%s'" % format)
             _regex_cache[format] = format_regex
     finally:
         _cache_lock.release()

diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
index f9763aa34c2c0c8a3adc4e901886cffbc497dc06..ba65649857ead0b028f7eb00dea10c822ed97c60 100644 (file)
--- a/Lib/test/test_strptime.py
+++ b/Lib/test/test_strptime.py
@@ -197,10 +197,20 @@ class StrptimeTests(unittest.TestCase):
         """Create testing time tuple."""
         self.time_tuple = time.gmtime()
 
-    def test_TypeError(self):
-        # Make sure ValueError is raised when match fails
+    def test_ValueError(self):
+        # Make sure ValueError is raised when match fails or format is bad
         self.assertRaises(ValueError, _strptime.strptime, data_string="%d",
                           format="%A")
+        for bad_format in ("%", "% ", "%e"):
+            try:
+                _strptime.strptime("2005", bad_format)
+            except ValueError:
+                continue
+            except Exception, err:
+                self.fail("'%s' raised %s, not ValueError" %
+                            (bad_format, err.__class__.__name__))
+            else:
+                self.fail("'%s' did not raise ValueError" % bad_format)
 
     def test_unconverteddata(self):
         # Check ValueError is raised when there is unconverted data

diff --git a/Misc/NEWS b/Misc/NEWS
index 9b3f3814bda1c1f35604c9eef8014dba8129d699..59f165a61e3a9c2840d56ceb300eaff461f84d46 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -276,6 +276,9 @@ Extension Modules
 Library
 -------
 
+- Bug #1340337: change time.strptime() to always return ValueError when there
+  is an error in the format string.
+
 - Patch #754022: Greatly enhanced webbrowser.py (by Oleg Broytmann).
 
 - Bug #729103: pydoc.py: Fix docother() method to accept additional