Resolve type errors; refactor non-pythonic code

Signed-off-by: Asadullah Shaikh <[email protected]>

picamera2/picamera2.py

@@ -270,12 +270,12 @@ def __init__(self, camera_num=0, verbose_console=None, tuning=None, allocator=No
             _log.debug(f"{self.camera_manager}")
             # We deliberately make raw streams with no size so that it will be filled in
             # later once the main stream size has been set.
-            self.preview_configuration = self.create_preview_configuration()
-            self.preview_configuration.enable_raw()  # causes the size to be reset to None
-            self.still_configuration = self.create_still_configuration()
-            self.still_configuration.enable_raw()  # ditto
-            self.video_configuration = self.create_video_configuration()
-            self.video_configuration.enable_raw()  # ditto
+            self.preview_configuration_ = CameraConfiguration(self.create_preview_configuration(), self)
+            self.preview_configuration_.enable_raw()  # causes the size to be reset to None
+            self.still_configuration_ = CameraConfiguration(self.create_still_configuration(), self)
+            self.still_configuration_.enable_raw()  # ditto
+            self.video_configuration_ = CameraConfiguration(self.create_video_configuration(), self)
+            self.video_configuration_.enable_raw()  # ditto
         except Exception:
             _log.error("Camera __init__ sequence did not complete.")
             raise RuntimeError("Camera __init__ sequence did not complete.")
@@ -425,12 +425,10 @@ def _grab_camera(self, idx):
         elif isinstance(idx, int):
             return self.camera_manager.cameras[idx]
 
-    def _initialize_camera(self) -> bool:
+    def _initialize_camera(self) -> None:
         """Initialize camera
 
         :raises RuntimeError: Failure to initialise camera
-        :return: True if success
-        :rtype: bool
         """
         if not self.camera_manager.cameras:
             _log.error("Camera(s) not found (Do not forget to disable legacy camera with raspi-config).")
@@ -458,7 +456,6 @@ def _initialize_camera(self) -> bool:
         self.sensor_format = self._native_mode['format']
 
         _log.info('Initialization successful.')
-        return True
 
     def __identify_camera(self):
         for idx, address in enumerate(self.camera_manager.cameras):
@@ -471,7 +468,9 @@ def _open_camera(self) -> None:
 
         :raises RuntimeError: Failed to setup camera
         """
-        if not self._initialize_camera():
+        try:
+            self._initialize_camera()
+        except RuntimeError:
             raise RuntimeError("Failed to initialize camera")
 
         # This now throws an error if it can't open the camera.
@@ -628,12 +627,12 @@ def close(self) -> None:
         self.streams = None
         self.stream_map = None
         self.camera = None
-        self.camera_ctrl_info = None
+        self.camera_ctrl_info = {}
         self.camera_config = None
         self.libcamera_config = None
-        self.preview_configuration_ = None
-        self.still_configuration_ = None
-        self.video_configuration_ = None
+        self.preview_configuration = {}
+        self.still_configuration = {}
+        self.video_configuration = {}
         self.notifymeread.close()
         os.close(self.notifyme_w)
         # Clean up the allocator