Define function display.

       This function is equivalent to print() under python,
       is equivalent to str() in dg-python.

src/dynamic_graph/entity.py

@@ -6,6 +6,10 @@
 import wrap, signal_base
 
 entityClassNameList = []
+if 'display' not in globals().keys():
+    def display(s):
+        print(s)
+
 
 def commandMethod(name, docstring) :
     def method(self, *arg):
@@ -80,10 +84,10 @@ class Entity (object) :
         Print the list of signals into standard output: temporary.
         """
         signals = self.signals()
-        print "--- <" +  self.name + "> signal list: "
+        display ("--- <" +  self.name + "> signal list: ")
         for s in signals[:-1]:
-            print "    |-- <" + str(s)
-        print "    `-- <" + str(signals[-1])
+            display("    |-- <" + str(s))
+        display("    `-- <" + str(signals[-1]))
 
     def signals(self) :
         """
@@ -108,7 +112,7 @@ class Entity (object) :
                 ctitle+=' '
             for docstr in wrap.entity_get_command_docstring(self.obj,cstr).split('\n'):
                 if (len(docstr)>0) and (not docstr.isspace()):
-                    print ctitle+"\t"+docstr
+                    display(ctitle+"\t"+docstr)
                     break
 
     def help( self,comm=None ):
@@ -119,7 +123,7 @@ class Entity (object) :
         if comm is None:
             self.globalHelp()
         else:
-            print comm+":\n"+wrap.entity_get_command_docstring(self.obj,comm)
+            display(comm+":\n"+wrap.entity_get_command_docstring(self.obj,comm))
 
 
     def __getattr__(self, name):

src/interpreter.cc

@@ -20,11 +20,12 @@
 // Python initialization commands
 namespace dynamicgraph {
   namespace python {
-    static const std::string pythonPrefix[4] = {
+    static const std::string pythonPrefix[5] = {
       "import sys\n",
       "import traceback\n",
       "if '' not in sys.path: sys.path.append('')\n",
       "sys.argv = ['']\n",
+      "def display(s): return str(s) if not s is None else None"
     };
   }
 }
@@ -43,6 +44,7 @@ Interpreter::Interpreter()
   PyRun_SimpleString(pythonPrefix[1].c_str());
   PyRun_SimpleString(pythonPrefix[2].c_str());
   PyRun_SimpleString(pythonPrefix[3].c_str());
+  PyRun_SimpleString(pythonPrefix[4].c_str());
   traceback_format_exception_ = PyDict_GetItemString
     (PyModule_GetDict(PyImport_AddModule("traceback")), "format_exception");
   assert(PyCallable_Check(traceback_format_exception_));
@@ -51,9 +53,9 @@ Interpreter::Interpreter()
 
 Interpreter::~Interpreter()
 {
-  Py_DECREF(mainmod_);
-  Py_DECREF(globals_);
-  Py_DECREF(traceback_format_exception_);
+  //Py_DECREF(mainmod_);
+  //Py_DECREF(globals_);
+  //Py_DECREF(traceback_format_exception_);
   Py_Finalize();
 }
 
@@ -103,6 +105,7 @@ void Interpreter::runPythonFile( std::string filename )
   PyRun_SimpleString(pythonPrefix[0].c_str());
   PyRun_SimpleString(pythonPrefix[1].c_str());
   PyRun_SimpleString(pythonPrefix[2].c_str());
+  PyRun_SimpleString(pythonPrefix[4].c_str());
   PyRun_SimpleFile(NULL, filename.c_str());
 }