[datasets] Fix check() function and add test

bob/pipelines/datasets/csv.py

@@ -94,15 +94,13 @@ class CSVDataset:
                 samples = samples[:limit]
             for pos, sample in enumerate(samples):
                 try:
-                    assert len(sample) == len(self.fieldnames), (
-                        f"Entry {pos} in subset {name} has {len(sample)} "
-                        f"entries instead of {len(self.fieldnames)} "
-                        f"(expected). Fix file '{self._subsets[name]}'"
-                    )
-                    sample.data  # triggers loading
+                    sample.data  # may trigger data loading
                     logger.info(f"{sample.key}: OK")
                 except Exception as e:
-                    logger.error(f"{sample.key}: {e}")
+                    logger.error(
+                        f"Found error loading entry {pos} in subset {name} "
+                        f"from file '{self._subsets[name]}': {e}"
+                        )
                     errors += 1
         return errors
 

bob/pipelines/datasets/json.py

@@ -114,14 +114,15 @@ class JSONDataset:
                     samples = samples[:limit]
                 for pos, sample in enumerate(samples):
                     try:
-                        assert len(sample) == len(self.fieldnames), (
-                            f"Entry {pos} in subset {name} of protocol "
-                            f"{proto} has {len(sample)} entries instead of "
-                            f"{len(self.fieldnames)} (expected). Fix file "
-                            f"'{self._protocols[proto]}'"
-                        )
-                        sample.data  # check data can be loaded
+                        sample.data  # may trigger data loading
                         logger.info(f"{sample.key}: OK")
+                    except Exception as e:
+                        logger.error(
+                            f"Found error loading entry {pos} in subset {name} "
+                            f"of protocol {proto} from file "
+                            f"'{self._protocols[proto]}': {e}"
+                            )
+                        errors += 1
                     except Exception as e:
                         logger.error(f"{sample.key}: {e}")
                         errors += 1

bob/pipelines/tests/test_datasets.py

@@ -46,6 +46,7 @@ def test_csv_loading():
             )
 
     dataset = CSVDataset(subsets, fieldnames, _raw_data_loader)
+    dataset.check()
 
     data = dataset.subsets()
 
@@ -81,6 +82,7 @@ def test_json_loading():
     dataset = JSONDataset(protocols, fieldnames, _raw_data_loader)
 
     data = dataset.subsets("default")
+    dataset.check()
 
     nose.tools.eq_(len(data["train"]), 75)
     for k in data["train"]: