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.
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 @@
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 *