fixed type check in surf.query.validate_statement() as per issue co…

…sminbasca#19
mromanello · Feb 14, 2019 · 0f12510 · 0f12510
1 parent 91fb072
commit 0f12510
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/surf/query/__init__.py b/surf/query/__init__.py
@@ -394,7 +394,11 @@ def __str__(self):
 
 def validate_statement(statement):
     if isinstance(statement, tuple(Query.STATEMENT_TYPES + [Query])):
-        if isinstance(statement, (list, tuple)):
+        # since `NamedGroup` inherits from `list` via `Group` here we want
+        # to use `type()` instead of `isinstance()` as we need to tell
+        # whether `statement` is e.g. a list/tuple or an instance of
+        # `NamedGroup`
+        if type(statement) in [list, tuple]:
             try:
                 s, p, o = statement
             except: