py: Use exceptions instead of returning error codes

We have multiple methods which return an error code, mimicking the C++
API. Using exceptions is more natural in the Python API, so change all
those methods to raise an Exception instead.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/py/examples/simple-cam.py

@@ -259,12 +259,7 @@ def main():
     allocator = libcam.FrameBufferAllocator(camera)
 
     for cfg in config:
-        ret = allocator.allocate(cfg.stream)
-        if ret < 0:
-            print('Can\'t allocate buffers')
-            return -1
-
-        allocated = len(allocator.buffers(cfg.stream))
+        allocated = allocator.allocate(cfg.stream)
         print(f'Allocated {allocated} buffers for stream')
 
     # --------------------------------------------------------------------
@@ -289,15 +284,9 @@ def main():
     requests = []
     for i in range(len(buffers)):
         request = camera.create_request()
-        if not request:
-            print('Can\'t create request')
-            return -1
 
         buffer = buffers[i]
-        ret = request.add_buffer(stream, buffer)
-        if ret < 0:
-            print('Can\'t set buffer for request')
-            return -1
+        request.add_buffer(stream, buffer)
 
         # Controls can be added to a request on a per frame basis.
         request.set_control(libcam.controls.Brightness, 0.5)

src/py/examples/simple-capture.py

@@ -43,8 +43,7 @@ def main():
 
     # Acquire the camera for our use
 
-    ret = cam.acquire()
-    assert ret == 0
+    cam.acquire()
 
     # Configure the camera
 
@@ -60,8 +59,7 @@ def main():
         w, h = [int(v) for v in args.size.split('x')]
         stream_config.size = libcam.Size(w, h)
 
-    ret = cam.configure(cam_config)
-    assert ret == 0
+    cam.configure(cam_config)
 
     print(f'Capturing {TOTAL_FRAMES} frames with {stream_config}')
 
@@ -83,15 +81,13 @@ def main():
         req = cam.create_request(i)
 
         buffer = allocator.buffers(stream)[i]
-        ret = req.add_buffer(stream, buffer)
-        assert ret == 0
+        req.add_buffer(stream, buffer)
 
         reqs.append(req)
 
     # Start the camera
 
-    ret = cam.start()
-    assert ret == 0
+    cam.start()
 
     # frames_queued and frames_done track the number of frames queued and done
 
@@ -101,8 +97,7 @@ def main():
     # Queue the requests to the camera
 
     for req in reqs:
-        ret = cam.queue_request(req)
-        assert ret == 0
+        cam.queue_request(req)
         frames_queued += 1
 
     # The main loop. Wait for the queued Requests to complete, process them,
@@ -155,13 +150,11 @@ def main():
 
     # Stop the camera
 
-    ret = cam.stop()
-    assert ret == 0
+    cam.stop()
 
     # Release the camera
 
-    ret = cam.release()
-    assert ret == 0
+    cam.release()
 
     return 0
 

src/py/examples/simple-continuous-capture.py

@@ -28,8 +28,7 @@ class CameraCaptureContext:
 
         # Acquire the camera for our use
 
-        ret = cam.acquire()
-        assert ret == 0
+        cam.acquire()
 
         # Configure the camera
 
@@ -37,8 +36,7 @@ class CameraCaptureContext:
 
         stream_config = cam_config.at(0)
 
-        ret = cam.configure(cam_config)
-        assert ret == 0
+        cam.configure(cam_config)
 
         stream = stream_config.stream
 
@@ -62,8 +60,7 @@ class CameraCaptureContext:
             req = cam.create_request(idx)
 
             buffer = allocator.buffers(stream)[i]
-            ret = req.add_buffer(stream, buffer)
-            assert ret == 0
+            req.add_buffer(stream, buffer)
 
             self.reqs.append(req)
 
@@ -73,13 +70,11 @@ class CameraCaptureContext:
     def uninit_camera(self):
         # Stop the camera
 
-        ret = self.cam.stop()
-        assert ret == 0
+        self.cam.stop()
 
         # Release the camera
 
-        ret = self.cam.release()
-        assert ret == 0
+        self.cam.release()
 
 
 # A container class for our state
@@ -145,8 +140,7 @@ class CaptureContext:
 
         for cam_ctx in self.camera_contexts:
             for req in cam_ctx.reqs:
-                ret = cam_ctx.cam.queue_request(req)
-                assert ret == 0
+                cam_ctx.cam.queue_request(req)
 
         # Use Selector to wait for events from the camera and from the keyboard
 
@@ -177,8 +171,7 @@ def main():
     # Start the cameras
 
     for cam_ctx in ctx.camera_contexts:
-        ret = cam_ctx.cam.start()
-        assert ret == 0
+        cam_ctx.cam.start()
 
     ctx.capture()