bpo-33812: Corrected astimezone for naive datetimes. (GH-7578)
A datetime object d is aware if d.tzinfo is not None and
d.tzinfo.utcoffset(d) does not return None. If d.tzinfo is None,
or if d.tzinfo is not None but d.tzinfo.utcoffset(d) returns None,
d is naive.
This commit ensures that instances with non-None d.tzinfo, but
d.tzinfo.utcoffset(d) returning None are treated as naive.
In addition, C acceleration code will raise TypeError if
d.tzinfo.utcoffset(d) returns an object with the type other than
timedelta.
* Updated the documentation.
Assume that the term "naive" is defined elsewhere and remove the
not entirely correct clarification. Thanks, Tim.
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index a7e5e0b..7d4cdac 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -2414,25 +2414,24 @@
base = cls(2000, 2, 29)
self.assertRaises(ValueError, base.replace, year=2001)
+ @support.run_with_tz('EDT4')
def test_astimezone(self):
- return # The rest is no longer applicable
- # Pretty boring! The TZ test is more interesting here. astimezone()
- # simply can't be applied to a naive object.
dt = self.theclass.now()
- f = FixedOffset(44, "")
- self.assertRaises(ValueError, dt.astimezone) # naive
+ f = FixedOffset(44, "0044")
+ dt_utc = dt.replace(tzinfo=timezone(timedelta(hours=-4), 'EDT'))
+ self.assertEqual(dt.astimezone(), dt_utc) # naive
self.assertRaises(TypeError, dt.astimezone, f, f) # too many args
self.assertRaises(TypeError, dt.astimezone, dt) # arg wrong type
- self.assertRaises(ValueError, dt.astimezone, f) # naive
- self.assertRaises(ValueError, dt.astimezone, tz=f) # naive
+ dt_f = dt.replace(tzinfo=f) + timedelta(hours=4, minutes=44)
+ self.assertEqual(dt.astimezone(f), dt_f) # naive
+ self.assertEqual(dt.astimezone(tz=f), dt_f) # naive
class Bogus(tzinfo):
def utcoffset(self, dt): return None
def dst(self, dt): return timedelta(0)
bog = Bogus()
self.assertRaises(ValueError, dt.astimezone, bog) # naive
- self.assertRaises(ValueError,
- dt.replace(tzinfo=bog).astimezone, f)
+ self.assertEqual(dt.replace(tzinfo=bog).astimezone(f), dt_f)
class AlsoBogus(tzinfo):
def utcoffset(self, dt): return timedelta(0)
@@ -2440,6 +2439,14 @@
alsobog = AlsoBogus()
self.assertRaises(ValueError, dt.astimezone, alsobog) # also naive
+ class Broken(tzinfo):
+ def utcoffset(self, dt): return 1
+ def dst(self, dt): return 1
+ broken = Broken()
+ dt_broken = dt.replace(tzinfo=broken)
+ with self.assertRaises(TypeError):
+ dt_broken.astimezone()
+
def test_subclass_datetime(self):
class C(self.theclass):