new: add find_by_key to Assembly

Author: gonzalocasas

src/compas/datastructures/assembly/assembly.py

@@ -201,3 +201,22 @@ def find(self, guid):
 
         return self.graph.node_attribute(key, "part")
 
+    def find_by_key(self, key):
+        """Find a part in the assembly by its key.
+
+        Parameters
+        ----------
+        key : int | str, optional
+            The identifier of the part in the assembly.
+
+        Returns
+        -------
+        :class:`~compas.datastructures.Part` | None
+            The identified part,
+            or None if the part can't be found.
+
+        """
+        if key not in self.graph.node:
+            return None
+
+        return self.graph.node_attribute(key, "part")

tests/compas/datastructures/test_assembly.py

@@ -41,3 +41,16 @@ def test_find():
 
     assembly.add_part(part)
     assert assembly.find(part.guid) == part
+
+
+def test_find_by_key():
+    assembly = Assembly()
+    part = Part()
+    assembly.add_part(part, key=2)
+    assert assembly.find_by_key(2) == part
+
+    part = Part()
+    assembly.add_part(part, key="6")
+    assert assembly.find_by_key("6") == part
+
+    assert assembly.find_by_key("100") is None