[libgpiod][PATCH v2 4/8] bindings: python: use suggestions from upgrade_pythoncapi.py

[Vincent Fazio <vfazio@gmail.com>]

The upgrade_pythoncapi.py script performs transforms on C extension
sources to use new syntax [0]. It's generally used with a shim header
for compatibility, but the header is not necessary for these changes.

The suggested changes are:

  * Use the `Py_IsNone` function introduced in CPython 3.10 [1] over
    direct comparison to `Py_None`

  * Use `PyObject_Free` instead of `PyObject_Del` since `PyObject_Del`
    has been aliased to `PyObject_Free` for nearly 24 years [2] and has
    been announced as deprecated [3]

  * Use the `Py_NewRef` function introduced in CPython 3.10 [4] to
    increment and return a new reference.

[0]: https://pythoncapi-compat.readthedocs.io/en/latest/index.html
[1]: https://github.com/python/cpython/commit/09bbebea163fe7303264cf4069c51d4d2f22fde4
[2]: https://github.com/python/cpython/commit/3e7b893899bdaa294a72e894694b099a1d370765
[3]: https://docs.python.org/3/c-api/allocation.html#deprecated-aliases
[4]: https://github.com/python/cpython/commit/53a03aafd5812018a3821a2e83063fd3d6cd2576

Signed-off-by: Vincent Fazio <vfazio@gmail.com>
---
 bindings/python/gpiod/ext/chip.c    | 11 +++--------
 bindings/python/gpiod/ext/common.c  |  2 +-
 bindings/python/gpiod/ext/request.c |  2 +-
 bindings/python/tests/gpiosim/ext.c |  2 +-
 4 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/bindings/python/gpiod/ext/chip.c b/bindings/python/gpiod/ext/chip.c
index be20869..4d96dd8 100644
--- a/bindings/python/gpiod/ext/chip.c
+++ b/bindings/python/gpiod/ext/chip.c
@@ -172,12 +172,7 @@ static PyObject *chip_get_line_name(chip_object *self, PyObject *args)
 		return Py_gpiod_SetErrFromErrno();
 
 	name = gpiod_line_info_get_name(info);
-	if (!name) {
-		Py_INCREF(Py_None);
-		line_name = Py_None;
-	} else {
-		line_name = PyUnicode_FromString(name);
-	}
+	line_name = (name) ? PyUnicode_FromString(name) : Py_NewRef(Py_None);
 
 	gpiod_line_info_free(info);
 
@@ -272,7 +267,7 @@ make_request_config(PyObject *consumer_obj, PyObject *event_buffer_size_obj)
 		return NULL;
 	}
 
-	if (consumer_obj != Py_None) {
+	if (!Py_IsNone(consumer_obj)) {
 		consumer = PyUnicode_AsUTF8(consumer_obj);
 		if (!consumer) {
 			gpiod_request_config_free(req_cfg);
@@ -282,7 +277,7 @@ make_request_config(PyObject *consumer_obj, PyObject *event_buffer_size_obj)
 		gpiod_request_config_set_consumer(req_cfg, consumer);
 	}
 
-	if (event_buffer_size_obj != Py_None) {
+	if (!Py_IsNone(event_buffer_size_obj)) {
 		event_buffer_size = PyLong_AsSize_t(event_buffer_size_obj);
 		if (PyErr_Occurred()) {
 			gpiod_request_config_free(req_cfg);
diff --git a/bindings/python/gpiod/ext/common.c b/bindings/python/gpiod/ext/common.c
index 62201b6..7d2dda7 100644
--- a/bindings/python/gpiod/ext/common.c
+++ b/bindings/python/gpiod/ext/common.c
@@ -12,7 +12,7 @@ void Py_gpiod_dealloc(PyObject *self)
 	if (ret < 0)
 		return;
 
-	PyObject_Del(self);
+	PyObject_Free(self);
 }
 
 PyObject *Py_gpiod_SetErrFromErrno(void)
diff --git a/bindings/python/gpiod/ext/request.c b/bindings/python/gpiod/ext/request.c
index 9940382..46e07ae 100644
--- a/bindings/python/gpiod/ext/request.c
+++ b/bindings/python/gpiod/ext/request.c
@@ -286,7 +286,7 @@ static PyObject *request_read_edge_events(request_object *self, PyObject *args)
 	if (!ret)
 		return NULL;
 
-	if (max_events_obj != Py_None) {
+	if (!Py_IsNone(max_events_obj)) {
 		max_events = PyLong_AsSize_t(max_events_obj);
 		if (PyErr_Occurred())
 			return NULL;
diff --git a/bindings/python/tests/gpiosim/ext.c b/bindings/python/tests/gpiosim/ext.c
index cb5611a..1ebd5af 100644
--- a/bindings/python/tests/gpiosim/ext.c
+++ b/bindings/python/tests/gpiosim/ext.c
@@ -116,7 +116,7 @@ static void chip_dealloc(PyObject *self)
 	if (ret < 0)
 		return;
 
-	PyObject_Del(self);
+	PyObject_Free(self);
 }
 
 static PyObject *chip_dev_path(chip_object *self, void *Py_UNUSED(ignored))
-- 
2.43.0