Make Selector class iterable (where the iterator returns valid select…

…ors for each identifier comprised by the class instance).

neurokernel/plsel.py

@@ -161,6 +161,13 @@ def __len__(self):
         else:
             return len(self._expanded)
 
+    def __iter__(self):
+        if self.nonempty:
+            for t in self._expanded:
+                yield (t,)
+        else:
+            yield ((),)
+
     def __repr__(self):
         return 'Selector(\'%s\')' % self._str
 

tests/test_plsel.py

@@ -116,6 +116,16 @@ def test_selector_prod_nonempty(self):
                               ('x', 1, 'a'), ('x', 1, 'b'), ('x', 1, 'c'))
         assert s.str == '/x[0:2]+[a,b,c]'
 
+    def test_selector_iter(self):
+        sel = Selector('/x[0:3]')
+        self.assertSequenceEqual([s for s in sel],
+                                 [(('x', 0),),
+                                  (('x', 1),),
+                                  (('x', 2),)])
+        sel = Selector('')
+        self.assertSequenceEqual([s for s in sel],
+                                 [((),)])
+
 class test_path_like_selector(TestCase):
     def setUp(self):
         self.df = df.copy()