Issue #6641: Original commit for this issue, r82053, introduced a

regression making datetime subclass' strptime return datetime rather
than subclass instances.  Fixed this bug and a few typos.

Author: abalkin

Lib/_strptime.py

@@ -17,7 +17,6 @@
 from re import IGNORECASE, ASCII
 from re import escape as re_escape
 from datetime import (date as datetime_date,
-                      datetime as datetime_datetime,
                       timedelta as datetime_timedelta,
                       timezone as datetime_timezone)
 try:
@@ -297,7 +296,7 @@ def _calc_julian_from_U_or_W(year, week_of_year, day_of_week, week_starts_Mon):
 
 
 def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
-    """Return a 2-tuple consisting of a time struct and an int containg
+    """Return a 2-tuple consisting of a time struct and an int containing
     the number of microseconds based on the input string and the
     format string."""
 
@@ -483,8 +482,8 @@ def _strptime_time(data_string, format="%a %b %d %H:%M:%S %Y"):
     tt = _strptime(data_string, format)[0]
     return time.struct_time(tt[:9])
 
-def _strptime_datetime(data_string, format="%a %b %d %H:%M:%S %Y"):
-    """Return a datetime instace based on the input string and the
+def _strptime_datetime(class_, data_string, format="%a %b %d %H:%M:%S %Y"):
+    """Return a class_ instance based on the input string and the
     format string."""
     tt, fraction = _strptime(data_string, format)
     gmtoff, tzname = tt[-2:]
@@ -497,4 +496,4 @@ def _strptime_datetime(data_string, format="%a %b %d %H:%M:%S %Y"):
             tz = datetime_timezone(tzdelta)
         args += (tz,)
 
-    return datetime_datetime(*args)
+    return class_(*args)

Lib/test/test_datetime.py

@@ -1100,8 +1100,13 @@ def strftime(self, format_spec):
             self.assertEqual(b.__format__(fmt), 'B')
 
     def test_resolution_info(self):
-        self.assertIsInstance(self.theclass.min, self.theclass)
-        self.assertIsInstance(self.theclass.max, self.theclass)
+        # XXX: Should min and max respect subclassing?
+        if issubclass(self.theclass, datetime):
+            expected_class = datetime
+        else:
+            expected_class = date
+        self.assertIsInstance(self.theclass.min, expected_class)
+        self.assertIsInstance(self.theclass.max, expected_class)
         self.assertIsInstance(self.theclass.resolution, timedelta)
         self.assertTrue(self.theclass.max > self.theclass.min)
 
@@ -1732,9 +1737,11 @@ def test_strptime(self):
 
         string = '2004-12-01 13:02:47.197'
         format = '%Y-%m-%d %H:%M:%S.%f'
-        expected = _strptime._strptime_datetime(string, format)
+        expected = _strptime._strptime_datetime(self.theclass, string, format)
         got = self.theclass.strptime(string, format)
         self.assertEqual(expected, got)
+        self.assertIs(type(expected), self.theclass)
+        self.assertIs(type(got), self.theclass)
 
         strptime = self.theclass.strptime
         self.assertEqual(strptime("+0002", "%z").utcoffset(), 2 * MINUTE)
@@ -1896,6 +1903,12 @@ def newmeth(self, start):
         self.assertEqual(dt2.newmeth(-7), dt1.year + dt1.month +
                                           dt1.second - 7)
 
+class TestSubclassDateTime(TestDateTime):
+    theclass = SubclassDatetime
+    # Override tests not designed for subclass
+    def test_roundtrip(self):
+        pass
+
 class SubclassTime(time):
     sub_var = 1
 

Modules/datetimemodule.c

@@ -4377,8 +4377,8 @@ datetime_strptime(PyObject *cls, PyObject *args)
         if(module == NULL)
             return NULL;
     }
-    return PyObject_CallMethod(module, "_strptime_datetime", "uu",
-                               string, format);
+    return PyObject_CallMethod(module, "_strptime_datetime", "Ouu",
+                               cls, string, format);
 }
 
 /* Return new datetime from date/datetime and time arguments. */