pygossmap: adds get_halfchannel

contrib/pyln-client/pyln/client/gossmap.py

@@ -263,6 +263,17 @@ def get_channel(self, short_channel_id: Union[ShortChannelId, str]):
             short_channel_id = ShortChannelId.from_str(short_channel_id)
         return self.channels.get(short_channel_id)
 
+    def get_halfchannel(self,
+                        short_channel_id: Union[ShortChannelId, str],
+                        direction: int):
+        """ Returns a GossmapHalfchannel identified by a scid and direction. """
+        assert short_channel_id is not None
+        if isinstance(short_channel_id, str):
+            short_channel_id = ShortChannelId.from_str(short_channel_id)
+        assert direction in [0, 1], "direction can only be 0 or 1"
+        channel = self.get_channel(short_channel_id)
+        return channel.half_channels[direction]
+
     def get_node(self, node_id: Union[GossmapNodeId, str]):
         """ Resolves a node by its public key node_id """
         if isinstance(node_id, str):

contrib/pyln-client/tests/test_gossmap.py

@@ -70,7 +70,7 @@ def test_gossmap_halfchannel(tmp_path):
     assert chan.node2 == n2
 
     half0 = chan.get_direction(0)
-    half1 = chan.get_direction(1)
+    half1 = g.get_halfchannel("103x1x1", 1)
     assert half0
     assert half1
     assert half0.direction == 0