Adding new built-in function sum, with docs and tests.
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index adefba2..0eb8357 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1798,6 +1798,66 @@
Without arguments, equivalent to locals().\n\
With an argument, equivalent to object.__dict__.");
+
+static PyObject*
+builtin_sum(PyObject *self, PyObject *args)
+{
+ PyObject *seq;
+ PyObject *result = NULL;
+ PyObject *temp, *item, *iter;
+
+ if (!PyArg_ParseTuple(args, "O|O:sum", &seq, &result))
+ return NULL;
+
+ iter = PyObject_GetIter(seq);
+ if (iter == NULL)
+ return NULL;
+
+ if (result == NULL) {
+ result = PyInt_FromLong(0);
+ if (result == NULL) {
+ Py_DECREF(iter);
+ return NULL;
+ }
+ } else {
+ /* reject string values for 'start' parameter */
+ if (PyObject_TypeCheck(result, &PyBaseString_Type)) {
+ PyErr_SetString(PyExc_TypeError,
+ "can't sum strings [use ''.join(seq) instead]");
+ Py_DECREF(result);
+ Py_DECREF(iter);
+ return NULL;
+ }
+ }
+
+ for(;;) {
+ item = PyIter_Next(iter);
+ if (item == NULL) {
+ /* error, or end-of-sequence */
+ if (PyErr_Occurred()) {
+ Py_DECREF(result);
+ result = NULL;
+ }
+ break;
+ }
+ temp = PyNumber_Add(result, item);
+ Py_DECREF(result);
+ Py_DECREF(item);
+ result = temp;
+ if (result == NULL)
+ break;
+ }
+ Py_DECREF(iter);
+ return result;
+}
+
+PyDoc_STRVAR(sum_doc,
+"sum(sequence, start=0) -> value\n\
+\n\
+Returns the sum of a sequence of numbers (NOT strings) plus the value\n\
+of parameter 'start'. When the sequence is empty, returns start.");
+
+
static PyObject *
builtin_isinstance(PyObject *self, PyObject *args)
{
@@ -2001,6 +2061,7 @@
{"repr", builtin_repr, METH_O, repr_doc},
{"round", builtin_round, METH_VARARGS, round_doc},
{"setattr", builtin_setattr, METH_VARARGS, setattr_doc},
+ {"sum", builtin_sum, METH_VARARGS, sum_doc},
#ifdef Py_USING_UNICODE
{"unichr", builtin_unichr, METH_VARARGS, unichr_doc},
#endif