Redmine #1487: added error messages to assert statements

structure_assignment/pipeline.py

@@ -85,9 +85,9 @@ class Runner:
             else:
                 classla_columns = classla_line.split('\t')
                 tagged_columns = tagged_line.split('\t')
-                assert len(classla_columns) == len(tagged_columns) == 10  # conllu columns
-                assert classla_columns[0] == tagged_columns[0]  # match index
-                assert classla_columns[1] == tagged_columns[1]  # match token
+                assert len(classla_columns) == 10, 'Missing token in classla-generated conllu ({})'.format(len(tagged_line)
+                assert len(tagged_columns) == 10, 'Missing token in pre-tagged conllu ({})'.format(len(classla_line)
+                assert classla_columns[1] == tagged_columns[1], 'Pre-tagged token form ({}) does not match classla-generated token form ({}).'.format(classla_tokens[0], tagged_columns[0])
                 merged_columns = [classla_columns[i] if i in (3,5,9) else tagged_columns[i] for i in range(10)]
                 merged_line = '\t'.join(merged_columns)
             merged_conllu_file.write(merged_line + '\n')