bpo-31222: Make (datetime|date|time).replace return subclass type in Pure Python (#4176)
diff --git a/Lib/datetime.py b/Lib/datetime.py
index 2f03847..67d8600 100644
--- a/Lib/datetime.py
+++ b/Lib/datetime.py
@@ -828,7 +828,7 @@
month = self._month
if day is None:
day = self._day
- return date(year, month, day)
+ return type(self)(year, month, day)
# Comparisons of date objects with other.
@@ -1316,7 +1316,7 @@
tzinfo = self.tzinfo
if fold is None:
fold = self._fold
- return time(hour, minute, second, microsecond, tzinfo, fold=fold)
+ return type(self)(hour, minute, second, microsecond, tzinfo, fold=fold)
# Pickle support.
@@ -1597,7 +1597,7 @@
tzinfo = self.tzinfo
if fold is None:
fold = self.fold
- return datetime(year, month, day, hour, minute, second,
+ return type(self)(year, month, day, hour, minute, second,
microsecond, tzinfo, fold=fold)
def _local_timezone(self):
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index c5f91fb..5b58e99 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -1520,6 +1520,13 @@
base = cls(2000, 2, 29)
self.assertRaises(ValueError, base.replace, year=2001)
+ def test_subclass_replace(self):
+ class DateSubclass(self.theclass):
+ pass
+
+ dt = DateSubclass(2012, 1, 1)
+ self.assertIs(type(dt.replace(year=2013)), DateSubclass)
+
def test_subclass_date(self):
class C(self.theclass):
@@ -2626,6 +2633,13 @@
self.assertRaises(ValueError, base.replace, second=100)
self.assertRaises(ValueError, base.replace, microsecond=1000000)
+ def test_subclass_replace(self):
+ class TimeSubclass(self.theclass):
+ pass
+
+ ctime = TimeSubclass(12, 30)
+ self.assertIs(type(ctime.replace(hour=10)), TimeSubclass)
+
def test_subclass_time(self):
class C(self.theclass):