[core][dataset] Fix typo when data is empty

darfix/core/dataset.py

@@ -796,6 +796,7 @@ class Dataset():
 
         io_utils.advancement_display(0, len(data), "Applying shift")
         if dimension is not None:
+
             # Convert dimension and value into list
             if type(dimension[0]) is int:
                 dimension[0] = [dimension[0]]
@@ -1550,7 +1551,6 @@ class Data(numpy.ndarray):
             del _file["dataset"]
             _file.create_dataset("dataset", new_shape, dtype=self.dtype)
 
-
         for i, img in enumerate(data):
             _file["dataset"][i] = img
             urls.append(DataUrl(file_path=path, data_path="/dataset", data_slice=i, scheme='silx'))
@@ -1628,7 +1628,9 @@ class Data(numpy.ndarray):
                 raise TypeError("Axis must be None, 0 or 1")
         else:
             if axis == 0:
-                if not data.shape[0]:
+                if data.size == 0:
+                    return numpy.array([])
+                elif not data.shape[0]:
                     return numpy.zeros(data[0].shape)
                 zsum = numpy.array(data[0], dtype=numpy.float64)
                 for i in range(1, len(data)):