Merge pull request #495 from DeepRegNet/481-improve-error-check-when-…

…data-path-is-wrong

Issue #481: check dataset is not empty for h5 and nifti

CHANGELOG.md

@@ -17,6 +17,7 @@ straightforward as possible.
 - Added max_epochs argument for training to overwrite configuration.
 - Added log_root argument for training and prediction to customize the log file
   location.
+- Added more meaningful error messages for data loading.
 - Added integration tests for all demos.
 - Added environment.yml file for Conda environment creation.
 - Added Dockerfile.

deepreg/dataset/loader/h5_loader.py

@@ -22,8 +22,8 @@ def __init__(self, dir_paths: List[str], name: str, grouped: bool):
         self.h5_files = None
         self.data_path_splits = None
         self.set_data_structure()
+        self.group_struct = None
         if self.grouped:
-            self.group_struct = None
             self.set_group_structure()
 
     def set_data_structure(self):
@@ -61,6 +61,11 @@ def set_data_structure(self):
             else:
                 # each element is (dir_path, data_key)
                 data_path_splits += [(dir_path, k) for k in sorted(h5_file.keys())]
+        if len(data_path_splits) == 0:
+            raise ValueError(
+                f"No data collected from {self.dir_paths} in H5FileLoader, "
+                f"please verify the path is correct."
+            )
         self.h5_files = h5_files
         self.data_path_splits = data_path_splits
 

deepreg/dataset/loader/nifti_loader.py

@@ -31,8 +31,8 @@ def __init__(self, dir_paths: List[str], name: str, grouped: bool):
         )
         self.data_path_splits = None
         self.set_data_structure()
+        self.group_struct = None
         if self.grouped:
-            self.group_struct = None
             self.set_group_structure()
 
     def set_data_structure(self):
@@ -70,6 +70,11 @@ def set_data_structure(self):
                 data_path_splits += [
                     (dir_path, file_path, suffix) for file_path, suffix in data_paths
                 ]
+        if len(data_path_splits) == 0:
+            raise ValueError(
+                f"No data collected from {self.dir_paths} in NiftiFileLoader, "
+                f"please verify the path is correct."
+            )
         self.data_path_splits = sorted(data_path_splits)
 
     def set_group_structure(self):