make bytes(o) respect __bytes__ #2415
This adds two new C-API functions: PyObject_Bytes and PyBytes_FromObject.
Reviewer: Barry
diff --git a/Objects/object.c b/Objects/object.c
index 79f8288..206bb88 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -453,6 +453,45 @@
return res;
}
+PyObject *
+PyObject_Bytes(PyObject *v)
+{
+ PyObject *bytesmeth, *result, *func;
+ static PyObject *bytesstring = NULL;
+
+ if (bytesstring == NULL) {
+ bytesstring = PyUnicode_InternFromString("__bytes__");
+ if (bytesstring == NULL)
+ return NULL;
+ }
+
+ if (v == NULL)
+ return PyBytes_FromString("<NULL>");
+
+ if (PyBytes_CheckExact(v)) {
+ Py_INCREF(v);
+ return v;
+ }
+
+ /* Doesn't create a reference */
+ func = _PyType_Lookup(Py_TYPE(v), bytesstring);
+ if (func != NULL) {
+ result = PyObject_CallFunctionObjArgs(func, v, NULL);
+ if (result == NULL)
+ return NULL;
+ if (!PyBytes_Check(result)) {
+ PyErr_Format(PyExc_TypeError,
+ "__bytes__ returned non-bytes (type %.200s)",
+ Py_TYPE(result)->tp_name);
+ Py_DECREF(result);
+ return NULL;
+ }
+ return result;
+ }
+ PyErr_Clear();
+ return PyBytes_FromObject(v);
+}
+
/* The new comparison philosophy is: we completely separate three-way
comparison from rich comparison. That is, PyObject_Compare() and
PyObject_Cmp() *just* use the tp_compare slot. And PyObject_RichCompare()