[Python][Bug FIxed] Properly handle the single robot wrapper constructor

src/python/robot_wrapper.py

@@ -21,26 +21,34 @@ from explog import exp
 import time
 
 class RobotWrapper:
-    def __init__(self,filename, root_joint = None):
-        self.modelFileName = filename
-        if(root_joint is None):
-            self.model = se3.buildModelFromUrdf(filename)
-        else:
-            self.model = se3.buildModelFromUrdf(filename, root_joint)
-        self.data = self.model.createData()
-        self.v0 = utils.zero(self.nv)
-        self.q0 = utils.zero(self.nq)
 
-    def __init__(self,filename, mesh_dir, root_joint = None):
-        if not "buildModelAndGeomFromUrdf" in dir(se3):
-          raise Exception('It seems that the Geometry Module has not been compiled with Pinocchio') 
-        self.modelFileName = filename
-        if(root_joint is None):
-            self.model, self.geometry_model = se3.buildModelAndGeomFromUrdf(filename,mesh_dir)
+    def __init__(self, filename, mesh_dir = None, root_joint = None):
+        if isinstance(mesh_dir, basestring):
+          build_model_and_geom = True
+        else: # Only load the model
+          build_model_and_geom = False
+          root_joint = mesh_dir
+      
+        self.model_filename = filename
+        if build_model_and_geom:
+          # Check if the module geometry of Pinocchio has been compiled
+          if not "buildModelAndGeomFromUrdf" in dir(se3):
+            raise Exception('It seems that the Geometry Module has not been compiled with Pinocchio') 
+          if(root_joint is None):
+              self.model, self.geometry_model = se3.buildModelAndGeomFromUrdf(filename,mesh_dir)
+          else:
+              self.model, self.geometry_model = se3.buildModelAndGeomFromUrdf(filename,mesh_dir,root_joint)
+
+          self.data = self.model.createData()
+          self.geometry_data = se3.GeometryData(self.data, self.geometry_model)
         else:
-            self.model, self.geometry_model = se3.buildModelAndGeomFromUrdf(filename,mesh_dir,root_joint)
-        self.data = self.model.createData()
-        self.geometry_data = se3.GeometryData(self.data, self.geometry_model)
+          if(root_joint is None):
+              self.model = se3.buildModelFromUrdf(filename)
+          else:
+              self.model = se3.buildModelFromUrdf(filename, root_joint)
+          
+          self.data = self.model.createData()
+
         self.v0 = utils.zero(self.nv)
         self.q0 = utils.zero(self.nq)