fix(robot): the first line of print(robot) names the class and the model

README.md

@@ -223,7 +223,7 @@ import roboticstoolbox as rtb
 robot = rtb.models.Panda()
 print(robot)
 
-	ERobot: panda (by Franka Emika), 7 joints (RRRRRRR), 1 gripper, geometry, collision
+	URDFRobot.Panda: panda (by Franka Emika), 7 joints (RRRRRRR), 1 gripper, geometry, collision
 	┌─────┬──────────────┬───────┬─────────────┬────────────────────────────────────────────────┐
 	│link │     link     │ joint │   parent    │              ETS: parent to link               │
 	├─────┼──────────────┼───────┼─────────────┼────────────────────────────────────────────────┤

src/roboticstoolbox/robot/BaseRobot.py

@@ -73,6 +73,10 @@ def _is_symbolic(value: Any) -> bool:
     return np.asarray(value).dtype == object
 
 
+# the modules of the robot classes themselves, as distinct from models built from them
+_FRAMEWORK_MODULES = ("roboticstoolbox.robot.", "roboticstoolbox.models.URDF.URDFRobot")
+
+
 class BaseRobot(SceneNode, DynamicsMixin, RobotPlottingMPLMixin, ABC, Generic[LinkType]):
     # set when the links are processed in the constructor
     _base_link: LinkType
@@ -531,9 +535,7 @@ def __str__(self) -> str:
                 f"{s}",
             )
 
-        classname = "ERobot"
-
-        s = f"{classname}: {self.name}"
+        s = f"{self._class_label()}: {self.name}"
         if self.manufacturer is not None and len(self.manufacturer) > 0:
             s += f" (by {self.manufacturer})"
         s += f", {self.n} joints ({self.structure})"
@@ -559,6 +561,20 @@ def __str__(self) -> str:
     def __repr__(self) -> str:
         return str(self)
 
+    def _class_label(self) -> str:
+        """
+        The class of this robot, for the first line of its display
+
+        ``Robot``, ``Robot2``, ``DHRobot`` or ``URDFRobot`` for an instance of the class
+        itself, and ``X.Y`` for an instance of a subclass ``Y`` of one of them, for
+        example ``DHRobot.Puma560`` or ``URDFRobot.Panda``: the kind of robot, then the
+        model.
+        """
+        cls = type(self)
+        if cls.__module__.startswith(_FRAMEWORK_MODULES):
+            return cls.__name__
+        return f"{cls.__mro__[1].__name__}.{cls.__name__}"
+
     # --------------------------------------------------------------------- #
     # --------- Properties ------------------------------------------------ #
     # --------------------------------------------------------------------- #

src/roboticstoolbox/robot/DHRobot.py

@@ -303,7 +303,7 @@ def __str__(self) -> str:
 
         unicode = rtb_get_param("unicode")
         border = "thin" if unicode else "ascii"
-        s = f"DHRobot: {self.name}"
+        s = f"{self._class_label()}: {self.name}"
 
         if self.manufacturer is not None and len(self.manufacturer) > 0:
             s += f" (by {self.manufacturer})"

tests/test_robot_label.py

@@ -0,0 +1,38 @@
+"""The first line of a robot's display names its class: the kind of robot, then the
+model, as ``DHRobot.Puma560``."""
+
+import roboticstoolbox as rtb
+
+
+def _first_line(robot):
+    return str(robot).splitlines()[0]
+
+
+def test_ets_model():
+    assert _first_line(rtb.models.ETS.Planar_Y()).startswith("Robot.Planar_Y: ")
+
+
+def test_urdf_model():
+    assert _first_line(rtb.models.URDF.Panda()).startswith("URDFRobot.Panda: ")
+
+
+def test_dh_model():
+    assert _first_line(rtb.models.DH.Puma560()).startswith("DHRobot.Puma560: ")
+
+
+def test_the_classes_themselves_have_no_model():
+    robot = rtb.Robot(rtb.ET.Rz() * rtb.ET.tx(1), name="arm")
+    dh = rtb.DHRobot([rtb.RevoluteDH(a=1.0)], name="dh")
+    robot2 = rtb.Robot2(rtb.ET2.R() * rtb.ET2.tx(1), name="flat")
+
+    assert _first_line(robot).startswith("Robot: arm")
+    assert _first_line(dh).startswith("DHRobot: dh")
+    assert _first_line(robot2).startswith("Robot2: flat")
+
+
+def test_a_users_own_subclass():
+    class Mine(rtb.Robot):
+        def __init__(self):
+            super().__init__(rtb.ET.Rz() * rtb.ET.tx(1), name="mine")
+
+    assert _first_line(Mine()).startswith("Robot.Mine: mine")