Convenience wrapper for datetime.timedelta.total_seconds()

Allows time deltas in seconds to be concisely calculated
for py26 and py27.

Change-Id: I8987af1f892fda0a72f5eb0d45f94c595792dc78

2 files changed, 20 insertions, 0 deletions

diff --git a/openstack/common/timeutils.py b/openstack/common/timeutils.py
index 8600439..4bf19a5 100644
--- a/openstack/common/timeutils.py
+++ b/openstack/common/timeutils.py
@@ -135,3 +135,16 @@ def unmarshall_time(tyme):
                              minute=tyme['minute'],
                              second=tyme['second'],
                              microsecond=tyme['microsecond'])
+
+
+def delta_seconds(before, after):
+    """
+    Compute the difference in seconds between two date, time, or
+    datetime objects (as a float, to microsecond resolution).
+    """
+    delta = after - before
+    try:
+        return delta.total_seconds()
+    except AttributeError:
+        return ((delta.days * 24 * 3600) + delta.seconds +
+                float(delta.microseconds) / (10 ** 6))
diff --git a/tests/unit/test_timeutils.py b/tests/unit/test_timeutils.py
index 38ac3ed..8236032 100644
--- a/tests/unit/test_timeutils.py
+++ b/tests/unit/test_timeutils.py
@@ -122,6 +122,13 @@ class TimeUtilsTest(unittest.TestCase):
         backagain = timeutils.unmarshall_time(binary)
         self.assertEqual(now, backagain)
 
+    def test_delta_seconds(self):
+        before = timeutils.utcnow()
+        after = before + datetime.timedelta(days=7, seconds=59,
+                                            microseconds=123456)
+        self.assertAlmostEquals(604859.123456,
+                                timeutils.delta_seconds(before, after))
+
 
 class TestIso8601Time(unittest.TestCase):