Added intersection() method to circuit ids (#192)

---------

Co-authored-by: Joni Herttuainen <joni.herttuainen@epfl.ch>

CHANGELOG.rst

@@ -4,6 +4,10 @@ Changelog
 Version v1.0.7
 --------------
 
+New Features
+~~~~~~~~~~~~
+- Added ``CircuitIds.intersection`` to take the intersection of two ``CircuitIds``.
+
 Bug Fixes
 ~~~~~~~~~
 - Fix CircuitIds.sample() to always return different samples.

bluepysnap/circuit_ids.py

@@ -253,6 +253,18 @@ def unique(self, inplace=False):
         """
         return self._apply(lambda x: x.unique(), inplace)
 
+    def intersection(self, circuit_ids, inplace=False):
+        """Take the intersection of this CircuitIds and the input.
+
+        The index of the resulting object is sorted if ``inplace=False``.
+        Otherwise, the orginal order of the index is kept.
+
+        Args:
+            circuit_ids (CircuitIds): The CircuitIds to intersect with.
+            inplace (bool): if set to True, do the transformation inplace.
+        """
+        return self._apply(lambda x: x.intersection(circuit_ids.index), inplace)
+
     def to_csv(self, filepath):
         """Save CircuitIds to csv format."""
         self.index.to_frame(index=False).to_csv(filepath, index=False)

tests/test_circuit_ids.py

@@ -209,6 +209,23 @@ def test_append(self):
         )
         assert test_obj == expected
 
+    def test_intersection(self):
+        test_obj = self.ids_cls.from_tuples(_multi_index(), sort_index=False)
+        other = self.ids_cls.from_tuples([("b", 0), ("a", 3), ("a", 2)], sort_index=False)
+        expected = self.ids_cls.from_tuples([("a", 2), ("b", 0)])
+        res = test_obj.intersection(other)
+
+        # res should be sorted when inplace=False
+        assert res == expected
+        assert test_obj != expected
+
+        res = test_obj.intersection(other, inplace=True)
+        assert res is None
+
+        # test_obj index should not be sorted when inplace=True
+        assert test_obj != expected
+        assert all(expected.index == test_obj.index.sort_values())
+
     def test_sample(self):
         with patch("numpy.random.choice", return_value=np.array([0, 3])):
             tested = self.test_obj_unsorted.sample(2, inplace=False)