Issue #8644: Improve accuracy of timedelta.total_seconds, by doing intermediate

computations with integer arithmetic instead of floating point.
td.total_seconds() now agrees with td / timedelta(seconds = 1).

Thanks Alexander Belopolsky for the patch.

1 files changed, 19 insertions, 3 deletions

diff --git a/Modules/datetimemodule.c b/Modules/datetimemodule.c
index 83dab2c..d4714bd 100644
--- a/Modules/datetimemodule.c
+++ b/Modules/datetimemodule.c
@@ -2211,9 +2211,25 @@ delta_getstate(PyDateTime_Delta *self)
 static PyObject *
 delta_total_seconds(PyObject *self)
 {
-	return PyFloat_FromDouble(GET_TD_MICROSECONDS(self) / 1000000.0 +
-				  GET_TD_SECONDS(self) +
-				  GET_TD_DAYS(self) * 24.0 * 3600.0);
+	PyObject *total_seconds;
+	PyObject *total_microseconds;
+	PyObject *one_million;
+
+	total_microseconds = delta_to_microseconds((PyDateTime_Delta *)self);
+	if (total_microseconds == NULL)
+		return NULL;
+
+	one_million = PyLong_FromLong(1000000L);
+	if (one_million == NULL) {
+		Py_DECREF(total_microseconds);
+		return NULL;
+	}
+
+	total_seconds = PyNumber_TrueDivide(total_microseconds, one_million);
+
+	Py_DECREF(total_microseconds);
+	Py_DECREF(one_million);
+	return total_seconds;
 }
 
 static PyObject *