When building python Entity classes, populate methods with docstrings.

     * src/dynamic-graph-py.cc,
     * src/dynamic_graph/entity.py,
     * src/entity-py.cc.

src/dynamic-graph-py.cc

@@ -30,6 +30,7 @@ namespace dynamicgraph {
       extern PyObject* displaySignals(PyObject* self, PyObject* args);
       extern PyObject* executeCommand(PyObject* self, PyObject* args);
       extern PyObject* listCommands(PyObject* self, PyObject* args);
+      extern PyObject* getCommandDocstring(PyObject* self, PyObject* args);
     }
 
     namespace factory {
@@ -137,6 +138,10 @@ static PyMethodDef dynamicGraphMethods[] = {
    dynamicgraph::python::entity::listCommands,
    METH_VARARGS,
    "list the commands of an entity"},
+  {"entity_get_command_docstring",
+   dynamicgraph::python::entity::getCommandDocstring,
+   METH_VARARGS,
+   "get the docstring of an entity command"},
   {"factory_get_entity_class_list",
    dynamicgraph::python::factory::getEntityClassList,
    METH_VARARGS,

src/dynamic_graph/entity.py

@@ -7,9 +7,10 @@ import wrap, signal_base
 
 entityClassNameList = []
 
-def commandMethod(name) :
+def commandMethod(name, docstring) :
     def method(self, *arg):
         return wrap.entity_execute_command(self.object, name, arg)
+    method.__doc__ = docstring
     return method
 
 def initEntity(self, name):
@@ -22,7 +23,8 @@ def initEntity(self, name):
         commands = wrap.entity_list_commands(self.object)
         # for each command, add a method with the name of the command
         for command in commands:
-            setattr(self.__class__, command, commandMethod(command))
+            docstring = wrap.entity_get_command_docstring(self.object, command)
+            setattr(self.__class__, command, commandMethod(command, docstring))
         self.__class__.commandCreated = True
 
 def updateEntityClasses(dictionary):

src/entity-py.cc

@@ -458,6 +458,32 @@ namespace dynamicgraph {
 	}
 	return result;
       }
+      PyObject* getCommandDocstring(PyObject* self, PyObject* args)
+      {
+	PyObject* object = NULL;
+	char* commandName;
+	if (!PyArg_ParseTuple(args, "Os", &object, &commandName)) {
+	  return NULL;
+	}
+
+	// Retrieve the entity instance
+	if (!PyCObject_Check(object)) {
+	  PyErr_SetString(error, "first argument is not an object");
+	  return NULL;
+	}
+	void* pointer = PyCObject_AsVoidPtr(object);
+	Entity* entity = (Entity*)pointer;
+	typedef	std::map<const std::string, command::Command*>  CommandMap;
+	CommandMap map = entity->getNewStyleCommandMap();
+	command::Command* command = NULL;
+	try {
+	  command = map[commandName];
+	} catch (const std::exception& exc) {
+	  PyErr_SetString(error, exc.what());
+	}
+	std::string docstring = command->getDocstring();
+	return Py_BuildValue("s", docstring.c_str());
+      }
     }
   }
 }