fix up reduce in rdf

The comparison is deprecated is `res` is a numpy array. This is more robust.
MDAnalysis · Sep 20, 2018 · 58b1281 · 58b1281
1 parent c248ca3
commit 58b1281
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/pmda/rdf.py b/pmda/rdf.py
@@ -164,7 +164,7 @@ def _conclude(self, ):
     @staticmethod
     def _reduce(res, result_single_frame):
         """ 'add' action for an accumulator"""
-        if res == []:
+        if isinstance(res, list) and len(res) == 0:
             # Convert res from an empty list to a numpy array
             # which has the same shape as the single frame result
             res = result_single_frame