Downgrade ERROR to WARNING for orphan branches #183

README.md

@@ -93,6 +93,10 @@ Goal for 0.4.0
 
 ### 0.3.x
 
+0.3.9
+
+- Issue #183
+
 0.3.8
 
 - Issue #171 is partially improved.

src/query_engine.py

@@ -242,13 +242,14 @@ def get_sequence(primary, reference):
                 if primary == previous_primary:
                     break 
             # a sequence can lose dependency half-way
-            # in which case an error message will be given
+            # in which case an warning message will be given
+            orphans = []
             for idx, item in enumerate(primary):
                 if idx == len(primary) - 1:
                     break
                 if self.depends is not None and primary[idx+1] not in self.depends[item]:
-                    raise ValueError(f'Requested module ``{primary[idx+1]}`` is an orphan branch. Please consider using separate queries for information from this module.')
-            return primary
+                    logger.warning(f'Requested module ``{primary[idx+1]}`` is an orphan branch with respect to module ``{item}``; thus removed from sub-query involving module ``{item}``.')
+            return [item for item in primary if not item in orphans]
         #
         valid_tables = [[item[0] for item in self.target_tables + self.condition_tables if item[0] in pipeline] for pipeline in pipelines]
         # 1. Further filter pipelines to minimally match target table dependencies
@@ -491,4 +492,4 @@ def warn(self):
 if __name__ == '__main__':
     import sys
     q = Query_Processor(sys.argv[1], [sys.argv[2]], [sys.argv[3]])
-    print(q.queries)
+    print(q.queries)