Return Graph in-edges as (source, target)

spatial_graph/graph/wrapper_template.pyx

@@ -291,7 +291,19 @@ cdef class Graph:
     def ${prefix}edges(self, node=None, bint data=False):
 
         if node is not None:
-            yield from self._${prefix}neighbors(<NodeType>node, data)
+            for neighbor in self._${prefix}neighbors(<NodeType>node, data):
+                if data:
+                    %if $prefix == "in_"
+                    yield (neighbor[0], node), data
+                    %else
+                    yield (node, neighbor[0]), data
+                    %end if
+                else:
+                    %if $prefix == "in_"
+                    yield (neighbor, node)
+                    %else
+                    yield (node, neighbor)
+                    %end if
             return
 
         cdef NodeIterator node_it = self._graph.begin()
@@ -314,11 +326,16 @@ cdef class Graph:
                     inc(it)
                     continue
                 %end if
+                %if $prefix == "in_"
+                edge = (v, u)
+                %else
+                edge = (u, v)
+                %end if
                 if data:
                     edge_data.set_ptr(&deref(it).second.prop())
-                    yield (u, v), edge_data
+                    yield edge, edge_data
                 else:
-                    yield (u, v)
+                    yield edge
                 inc(it)
             inc(node_it)
 
@@ -340,8 +357,13 @@ cdef class Graph:
             end = view.second
             while it != end:
                 v = deref(it).first
+                %if $prefix == "in_"
+                edges[i, 0] = v
+                edges[i, 1] = u
+                %else
                 edges[i, 0] = u
                 edges[i, 1] = v
+                %end if
                 i += 1
                 inc(it)
 

tests/test_graph.py

@@ -61,7 +61,7 @@ def test_operations(directed):
             assert attrs.score == edge[0] * 100 + edge[1]
 
         for edge, attrs in graph.in_edges(data=True):
-            assert attrs.score == edge[1] * 100 + edge[0]
+            assert attrs.score == edge[0] * 100 + edge[1]
 
     else:
         assert graph.num_edges() == (len(nodes) ** 2 - len(nodes)) / 2
@@ -75,6 +75,36 @@ def test_operations(directed):
             assert attrs.score == edge[0] * 100 + edge[1]
 
 
+def test_directed_edges():
+
+    graph = sg.Graph("uint64", directed=True)
+    graph.add_nodes(np.array([0, 1, 2], dtype="uint64"))
+    graph.add_edges(np.array([[0, 1], [1, 2], [2, 0]], dtype="uint64"))
+
+    # all in edges
+    in_edges = sorted(list(graph.in_edges()))
+    assert len(in_edges) == 3
+    np.testing.assert_array_equal(in_edges, [[0, 1], [1, 2], [2, 0]])
+
+    # all out edges
+    out_edges = sorted(list(graph.out_edges()))
+    assert len(out_edges) == 3
+    np.testing.assert_array_equal(out_edges, [[0, 1], [1, 2], [2, 0]])
+
+    # in/out edges per node
+    in_edges_0 = list(graph.in_edges(0))
+    assert len(in_edges_0) == 1
+    np.testing.assert_array_equal(in_edges_0, [[2, 0]])
+    out_edges_0 = list(graph.out_edges(0))
+    assert len(out_edges_0) == 1
+    np.testing.assert_array_equal(out_edges_0, [[0, 1]])
+
+    # in/out edges for list of nodes
+    in_edges_01 = graph.in_edges_by_nodes(np.array([0, 1], dtype="uint64"))
+    np.testing.assert_array_equal(in_edges_01, [[2, 0], [0, 1]])
+    out_edges_01 = graph.out_edges_by_nodes(np.array([0, 1], dtype="uint64"))
+    np.testing.assert_array_equal(out_edges_01, [[0, 1], [1, 2]])
+
 def test_attribute_modification():
     graph = sg.Graph(
         "uint64",