Drop find_ prefix in Python MjSpec methods accessing elements by name.

PiperOrigin-RevId: 725594833
Change-Id: Ibf8a9918e98b298751d0ef2e657714e28e5fa460

doc/python.rst

@@ -589,9 +589,8 @@ to make model editing easier:
 
 Finding elements
 ^^^^^^^^^^^^^^^^
-The ``MjSpec`` object has methods like ``find_body(), find_joint(), find_site(), ...`` for every type of name-able
-:ref:`mjtObj` type. These methods take a name string and return the element with that name or ``None`` if it does not
-exist.
+The ``MjSpec`` object has methods like ``.body(), .joint(), .site(), ...`` for named access of elements.
+``spec.geom('my_geom')`` will return the :ref:`mjsGeom` called "my_geom", or ``None`` if it does not exist.
 
 Element lists
 ^^^^^^^^^^^^^

python/mjspec.ipynb

@@ -573,11 +573,11 @@
     "    self.spec = mj.MjSpec.from_string(leg_model)\n",
     "\n",
     "    # Thigh:\n",
-    "    thigh = self.spec.find_body('thigh')\n",
+    "    thigh = self.spec.body('thigh')\n",
     "    thigh.add_geom(fromto=[0, 0, 0, length, 0, 0], size=[length/4, 0, 0], rgba=rgba)\n",
     "\n",
     "    # Hip:\n",
-    "    shin = self.spec.find_body('shin')\n",
+    "    shin = self.spec.body('shin')\n",
     "    shin.add_geom(fromto=[0, 0, 0, 0, 0, -length], size=[length/5, 0, 0], rgba=rgba)\n",
     "    shin.pos[0] = length"
    ]
@@ -620,6 +620,7 @@
     "  \"\"\"Constructs a creature with `num_legs` legs.\"\"\"\n",
     "  rgba = random_state.uniform([0, 0, 0, 1], [1, 1, 1, 1])\n",
     "  spec = mj.MjSpec.from_string(creature_model)\n",
+    "  spec.copy_during_attach = True\n",
     "\n",
     "  # Attach legs to equidistant sites on the circumference.\n",
     "  spec.worldbody.first_geom().rgba = rgba\n",
@@ -628,7 +629,7 @@
     "    theta = 2 * i * np.pi / num_legs\n",
     "    hip_pos = BODY_RADIUS * np.array([np.cos(theta), np.sin(theta), 0])\n",
     "    hip_site = spec.worldbody.add_site(pos=hip_pos, euler=[0, 0, theta])\n",
-    "    hip_site.attach_body(leg.spec.find_body('thigh'), '', '-' + str(i))\n",
+    "    hip_site.attach_body(leg.spec.body('thigh'), '', '-' + str(i))\n",
     "\n",
     "  return spec"
    ]
@@ -870,7 +871,7 @@
     "# # Add another humanoid\n",
     "spec_humanoid = mj.MjSpec.from_file(humanoid_file)\n",
     "attachment_frame = spec.worldbody.add_frame(pos=[0, -1, 2])\n",
-    "attachment_frame.attach_body(spec_humanoid.find_body('torso'), 'a', 'b')\n",
+    "attachment_frame.attach_body(spec_humanoid.body('torso'), 'a', 'b')\n",
     "\n",
     "# Recompile preserving the state\n",
     "new_model, new_data = spec.recompile(model, data)\n",
@@ -924,13 +925,14 @@
     "#@title Humanoid with arms replaced by legs.{vertical-output: true}\n",
     "\n",
     "spec = mj.MjSpec.from_file(humanoid_file)\n",
+    "spec.copy_during_attach = True\n",
     "\n",
     "# Get the torso, arm, and leg bodies\n",
-    "arm_left = spec.find_body('upper_arm_left')\n",
-    "arm_right = spec.find_body('upper_arm_right')\n",
-    "leg_left = spec.find_body('thigh_left')\n",
-    "leg_right = spec.find_body('thigh_right')\n",
-    "torso = spec.find_body('torso')\n",
+    "arm_left = spec.body('upper_arm_left')\n",
+    "arm_right = spec.body('upper_arm_right')\n",
+    "leg_left = spec.body('thigh_left')\n",
+    "leg_right = spec.body('thigh_right')\n",
+    "torso = spec.body('torso')\n",
     "\n",
     "# Attach frames at the arm positions\n",
     "shoulder_left = torso.add_frame(pos=arm_left.pos)\n",
@@ -976,13 +978,13 @@
     "  spec.degree = False  # MuJoCo release\n",
     "\n",
     "# Replace right arm with frame\n",
-    "arm_right = spec.find_body('upper_arm_right')\n",
-    "torso = spec.find_body('torso')\n",
+    "arm_right = spec.body('upper_arm_right')\n",
+    "torso = spec.body('torso')\n",
     "shoulder_right = torso.add_frame(pos=arm_right.pos, quat=[0, 0.8509035, 0, 0.525322])\n",
     "spec.detach_body(arm_right)\n",
     "\n",
     "# Attach Franka arm to humanoid\n",
-    "franka_arm = franka.find_body('fr3_link2')\n",
+    "franka_arm = franka.body('fr3_link2')\n",
     "shoulder_right.attach_body(franka_arm, 'franka', '')\n",
     "\n",
     "model = spec.compile()\n",
@@ -1033,6 +1035,7 @@
     "\n",
     "humanoid = mj.MjSpec.from_file(humanoid_file)\n",
     "spec = mj.MjSpec()\n",
+    "spec.copy_during_attach = True\n",
     "\n",
     "# Delete all key frames to avoid name conflicts\n",
     "while humanoid.keys:\n",
@@ -1044,18 +1047,18 @@
     "    humanoid.materials[0].rgba = [\n",
     "        np.random.uniform(), np.random.uniform(),\n",
     "        np.random.uniform(), 1]  # Randomize color\n",
-    "    humanoid.find_body('head').first_geom().size = [\n",
+    "    humanoid.body('head').first_geom().size = [\n",
     "        .18*np.random.uniform(), 0, 0]  # Randomize head size\n",
-    "    humanoid.find_body('upper_arm_left').quat = [\n",
+    "    humanoid.body('upper_arm_left').quat = [\n",
     "        np.random.uniform(), np.random.uniform(),\n",
     "        np.random.uniform(), np.random.uniform()]  # Randomize left arm orientation\n",
-    "    humanoid.find_body('upper_arm_right').quat = [\n",
+    "    humanoid.body('upper_arm_right').quat = [\n",
     "        np.random.uniform(), np.random.uniform(),\n",
     "        np.random.uniform(), np.random.uniform()]  # Randomize right arm orientation\n",
     "\n",
     "    # attach randomized humanoid to parent spec\n",
     "    frame = spec.worldbody.add_frame(pos=[i, j, 0])\n",
-    "    frame.attach_body(humanoid.find_body('torso'), str(i), str(j))\n",
+    "    frame.attach_body(humanoid.body('torso'), str(i), str(j))\n",
     "\n",
     "spec.worldbody.add_light(mode=mj.mjtCamLight.mjCAMLIGHT_TARGETBODYCOM,\n",
     "                         targetbody='3torso3', diffuse=[.8, .8, .8],\n",
@@ -1072,8 +1075,7 @@
     "sJFuNetilv4m"
    ],
    "gpuClass": "premium",
-   "private_outputs": true,
-   "toc_visible": true
+   "private_outputs": true
   },
   "gpuClass": "premium",
   "kernelspec": {

python/mujoco/codegen/generate_spec_bindings.py

@@ -583,7 +583,7 @@ def generate_find() -> None:
     elemlower = elem.lower()
     titlecase = 'Mjs' + elem
     code = f"""\n
-      mjSpec.def("find_{elemlower}",
+      mjSpec.def("{elemlower}",
       [](MjSpec& self, std::string& name) -> raw::{titlecase}* {{
         return mjs_as{elem}(
             mjs_findElement(self.ptr, {objtype}, name.c_str()));

python/mujoco/specs_test.py

@@ -617,12 +617,12 @@ def test_element_list(self):
     self.assertEqual(spec.actuators[0].name, 'actuator1')
     self.assertEqual(spec.actuators[1].name, 'actuator2')
     self.assertEqual(spec.actuators[2].name, 'actuator3')
-    self.assertEqual(spec.find_sensor('sensor1'), sensor1)
-    self.assertEqual(spec.find_sensor('sensor2'), sensor2)
-    self.assertEqual(spec.find_sensor('sensor3'), sensor3)
-    self.assertEqual(spec.find_actuator('actuator1'), actuator1)
-    self.assertEqual(spec.find_actuator('actuator2'), actuator2)
-    self.assertEqual(spec.find_actuator('actuator3'), actuator3)
+    self.assertEqual(spec.sensor('sensor1'), sensor1)
+    self.assertEqual(spec.sensor('sensor2'), sensor2)
+    self.assertEqual(spec.sensor('sensor3'), sensor3)
+    self.assertEqual(spec.actuator('actuator1'), actuator1)
+    self.assertEqual(spec.actuator('actuator2'), actuator2)
+    self.assertEqual(spec.actuator('actuator3'), actuator3)
 
   def test_body_list(self):
     main_xml = """
@@ -709,12 +709,12 @@ def test_geom_list(self):
     spec = mujoco.MjSpec.from_string(main_xml)
     geom1 = spec.worldbody.add_geom(name='geom1')
     geom2 = spec.worldbody.add_geom(name='geom2')
-    geom3 = spec.find_body('body1').add_geom(name='geom3')
+    geom3 = spec.body('body1').add_geom(name='geom3')
 
     self.assertEqual(spec.geoms, [geom1, geom2, geom3])
-    self.assertEqual(spec.find_geom('geom1'), geom1)
-    self.assertEqual(spec.find_geom('geom2'), geom2)
-    self.assertEqual(spec.find_geom('geom3'), geom3)
+    self.assertEqual(spec.geom('geom1'), geom1)
+    self.assertEqual(spec.geom('geom2'), geom2)
+    self.assertEqual(spec.geom('geom3'), geom3)
 
   def test_iterators(self):
     spec = mujoco.MjSpec()
@@ -801,11 +801,11 @@ def test_delete(self):
     self.assertEqual(model.nsite, 11)
     self.assertEqual(model.nsensor, 11)
 
-    head = spec.find_body('head')
+    head = spec.body('head')
     self.assertIsNotNone(head)
     site = head.first_site()
     self.assertIsNotNone(site)
-    self.assertEqual(site, spec.find_site('head'))
+    self.assertEqual(site, spec.site('head'))
 
     site.delete()
     spec.sensors[-1].delete()