refactored input validation for get_video and get_frames into their o…

…wn private methods

src/roiextractors/extractors/numpyextractors/numpyextractors.py

@@ -65,17 +65,7 @@ def __init__(self, timeseries: Union[PathType, np.ndarray], sampling_frequency:
         self._dtype = self._video.dtype
 
     def get_video(self, start_frame: Optional[int] = None, end_frame: Optional[int] = None) -> np.ndarray:
-        num_frames = self.get_num_frames()
-        start_frame = start_frame if start_frame is not None else 0
-        end_frame = end_frame if end_frame is not None else num_frames
-        assert 0 <= start_frame < num_frames, f"'start_frame' must be in [0, {num_frames}) but got {start_frame}"
-        assert 0 < end_frame <= num_frames, f"'end_frame' must be in (0, {num_frames}] but got {end_frame}"
-        assert (
-            start_frame <= end_frame
-        ), f"'start_frame' ({start_frame}) must be less than or equal to 'end_frame' ({end_frame})"
-        assert isinstance(start_frame, IntType), "'start_frame' must be an integer"
-        assert isinstance(end_frame, IntType), "'end_frame' must be an integer"
-
+        start_frame, end_frame = self._validate_get_video_arguments(start_frame=start_frame, end_frame=end_frame)
         return self._video[start_frame:end_frame, ...]
 
     def get_image_size(self) -> Tuple[int, int]:

src/roiextractors/imagingextractor.py

@@ -77,9 +77,9 @@ def get_video(self, start_frame: Optional[int] = None, end_frame: Optional[int]
         Parameters
         ----------
         start_frame: int, optional
-            Start frame index (inclusive).
+            Start frame index (inclusive). By default, it is set to 0.
         end_frame: int, optional
-            End frame index (exclusive).
+            End frame index (exclusive). By default, it is set to the number of frames.
 
         Returns
         -------
@@ -102,6 +102,38 @@ def get_video(self, start_frame: Optional[int] = None, end_frame: Optional[int]
         """
         pass
 
+    def _validate_get_video_arguments(
+        self, start_frame: Optional[int] = None, end_frame: Optional[int] = None
+    ) -> Tuple[int, int]:
+        """Validate the start_frame and end_frame arguments for the get_video method.
+
+        Parameters
+        ----------
+        start_frame: int, optional
+            Start frame index (inclusive). By default, it is set to 0.
+        end_frame: int, optional
+            End frame index (exclusive). By default, it is set to the number of frames.
+
+        Returns
+        -------
+        start_frame: int
+            Start frame index (inclusive).
+        end_frame: int
+            End frame index (exclusive).
+        """
+        num_frames = self.get_num_frames()
+        start_frame = start_frame if start_frame is not None else 0
+        end_frame = end_frame if end_frame is not None else num_frames
+        assert 0 <= start_frame < num_frames, f"'start_frame' must be in [0, {num_frames}) but got {start_frame}"
+        assert 0 < end_frame <= num_frames, f"'end_frame' must be in (0, {num_frames}] but got {end_frame}"
+        assert (
+            start_frame <= end_frame
+        ), f"'start_frame' ({start_frame}) must be less than or equal to 'end_frame' ({end_frame})"
+        # python 3.9 doesn't support get_instance on a Union of types, so we use get_args
+        assert isinstance(start_frame, get_args(IntType)), "'start_frame' must be an integer"
+        assert isinstance(end_frame, get_args(IntType)), "'end_frame' must be an integer"
+        return start_frame, end_frame
+
     def get_frames(self, frame_idxs: ArrayType) -> np.ndarray:
         """Get specific video frames from indices (not necessarily continuous).
 
@@ -115,14 +147,33 @@ def get_frames(self, frame_idxs: ArrayType) -> np.ndarray:
         frames: numpy.ndarray
             The video frames.
         """
+        start_frame, end_frame = self._validate_get_frames_arguments(frame_idxs=frame_idxs)
+        relative_indices = np.array(frame_idxs) - start_frame
+        return self.get_video(start_frame=start_frame, end_frame=end_frame)[relative_indices, ...]
+
+    def _validate_get_frames_arguments(self, frame_idxs: ArrayType) -> Tuple[int, int]:
+        """Validate the frame_idxs argument for the get_frames method.
+
+        Parameters
+        ----------
+        frame_idxs: array-like
+            Indices of frames to return.
+
+        Returns
+        -------
+        start_frame: int
+            Start frame index (inclusive).
+        end_frame: int
+            End frame index (exclusive).
+        """
         start_frame = min(frame_idxs)
         end_frame = max(frame_idxs) + 1
         assert start_frame >= 0, f"All 'frame_idxs' must be greater than or equal to zero but received {start_frame}."
         assert (
             end_frame <= self.get_num_frames()
         ), f"All 'frame_idxs' must be less than the number of frames ({self.get_num_frames()}) but received {end_frame}."
-        relative_indices = np.array(frame_idxs) - start_frame
-        return self.get_video(start_frame=start_frame, end_frame=end_frame)[relative_indices, ...]
+
+        return start_frame, end_frame
 
     def frame_to_time(self, frames: ArrayType) -> Union[FloatType, np.ndarray]:
         """Convert user-inputted frame indices to times with units of seconds.
@@ -298,17 +349,7 @@ def get_frames(self, frame_idxs: ArrayType) -> np.ndarray:
         return self._parent_imaging.get_frames(frame_idxs=mapped_frame_idxs)
 
     def get_video(self, start_frame: Optional[int] = None, end_frame: Optional[int] = None) -> np.ndarray:
-        num_frames = self.get_num_frames()
-        start_frame = start_frame if start_frame is not None else 0
-        end_frame = end_frame if end_frame is not None else num_frames
-        assert 0 <= start_frame < num_frames, f"'start_frame' must be in [0, {num_frames}) but got {start_frame}"
-        assert 0 < end_frame <= num_frames, f"'end_frame' must be in (0, {num_frames}] but got {end_frame}"
-        assert (
-            start_frame <= end_frame
-        ), f"'start_frame' ({start_frame}) must be less than or equal to 'end_frame' ({end_frame})"
-        # python 3.9 doesn't support get_instance on a Union of types, so we use get_args
-        assert isinstance(start_frame, get_args(IntType)), "'start_frame' must be an integer"
-        assert isinstance(end_frame, get_args(IntType)), "'end_frame' must be an integer"
+        start_frame, end_frame = self._validate_get_video_arguments(start_frame=start_frame, end_frame=end_frame)
 
         start_frame_shifted = start_frame + self._start_frame
         end_frame_shifted = end_frame + self._start_frame