[1.8.x] Fixed #24897 -- Allowed using choices longer than 1 day with DurationField

Backport of 262d4db8c4 from master

django/utils/dateparse.py

@@ -29,7 +29,7 @@ datetime_re = re.compile(
 
 standard_duration_re = re.compile(
     r'^'
-    r'(?:(?P<days>-?\d+) )?'
+    r'(?:(?P<days>-?\d+) (days?, )?)?'
     r'((?:(?P<hours>\d+):)(?=\d+:\d+))?'
     r'(?:(?P<minutes>\d+):)?'
     r'(?P<seconds>\d+)'

docs/releases/1.8.3.txt

@@ -40,3 +40,6 @@ Bugfixes
 
 * Fixed queryset pickling when using ``prefetch_related()`` after deleting
   objects (:ticket:`24831`).
+
+* Allowed using ``choices`` longer than 1 day with ``DurationField``
+  (:ticket:`24897`).

tests/utils_tests/test_dateparse.py

@@ -51,6 +51,20 @@ class DateParseTests(unittest.TestCase):
 
 
 class DurationParseTests(unittest.TestCase):
+
+    def test_parse_python_format(self):
+        timedeltas = [
+            timedelta(days=4, minutes=15, seconds=30, milliseconds=100),  # fractions of seconds
+            timedelta(hours=10, minutes=15, seconds=30),  # hours, minutes, seconds
+            timedelta(days=4, minutes=15, seconds=30),  # multiple days
+            timedelta(days=1, minutes=00, seconds=00),  # single day
+            timedelta(days=-4, minutes=15, seconds=30),  # negative durations
+            timedelta(minutes=15, seconds=30),  # minute & seconds
+            timedelta(seconds=30),  # seconds
+        ]
+        for delta in timedeltas:
+            self.assertEqual(parse_duration(format(delta)), delta)
+
     def test_seconds(self):
         self.assertEqual(parse_duration('30'), timedelta(seconds=30))