c++ 调用 python

xiguaqq20

　　

• Makefile first:g++ t2.cpp -o t2 -I/usr/include/python2.7 -lpython2.7 　　
  
• t2.cpp code
  
  #include
  #include
  #include
  
  void printDict(PyObject* obj)
  {
      if(!PyDict_Check(obj))
          return ;
  
      PyObject *k, *keys;
      keys = PyDict_Keys(obj);
  
      for(int i=0; i < PyList_GET_SIZE(keys); i++)
      {
          k = PyList_GET_ITEM(keys, i);
          char *c_name = PyString_AsString(k);
          printf("%s\n", c_name);
      }
  }
  
  int main(void)
  {
      Py_Initialize();
      if(!Py_IsInitialized())
          return -1;
     
      PyRun_SimpleString("import sys");
      //where you put your py file
      PyRun_SimpleString("sys.path.append('../')");
      //Import
      PyObject* pModule = PyImport_ImportModule("pc");//no *.py
      if(!pModule)
      {
          printf("can't open python file!\n");
          return -1;
      }
      //Dict module
      PyObject* pDict = PyModule_GetDict(pModule);
      if(!pDict)
      {
          printf("can't find dictionary.\n");
          return -1;
      }
      printDict(pDict);
  
      PyObject *pFunHi = PyDict_GetItemString(pDict, "sayHi");
      PyObject_CallFunction(pFunHi, "s", "yourname");// @para1: obj, @para2: name
      //release
      Py_DECREF(pFunHi);
     
      //Contruct a obj , call it's function
      //Second Class
      PyObject *pClassSecond = PyDict_GetItemString(pDict , "Second");
      if(!pClassSecond)
      {
          printf("can't find second class.\n");
          return -1;
      }
      //Person Class
      PyObject *pClassPerson = PyDict_GetItemString(pDict, "Person");
      if(!pClassPerson)
      {
          printf("can't find Person class.\n");
          return -1;
      }
      //Construct Second Instance
      PyObject* pInstanceSecond = PyInstance_New(pClassSecond, NULL, NULL);
      if(!pInstanceSecond)
      {
          printf("can't create second instance.\n");
          return -1;
      }
      //Construct Person Instance
      PyObject *pInstancePerson = PyInstance_New(pClassPerson, NULL, NULL);
      if(!pInstancePerson)
      {
          printf("can't create Person instance.\n");
          return -1;
      }
  
      //pass Person Instance to Second Instance
      PyObject_CallMethod(pInstanceSecond, "invoke", "O", pInstancePerson);
      PyObject_CallMethod(pInstanceSecond, "method2", "O", pInstancePerson);
  
      //call execute a py file
      PyRun_SimpleString("exec(compile(open('./1.py').read(),'1.py', 'exec'),locals(), globals())");
      //release
      Py_DECREF(pInstanceSecond);
      Py_DECREF(pInstancePerson);
      Py_DECREF(pClassSecond);
      Py_DECREF(pClassPerson);
      Py_DECREF(pModule);
      Py_Finalize();
  
      return 0;
  }
  
• pc.py ( I put it at ..(upper) dir )
  
  #!/usr/bin/python
  
  class Person:
      def sayHi(self):
          print 'Hi'
  
  class Second:
      def invoke(self, obj):
          obj.sayHi()
      def method2(self, obj):
          print "this is method2"
  
  def sayHi(name):
      print 'Hi ,', name
  
• 
  1.py ( I put it at .(this) dir )　　#!/usr/bin/python
  
  
  
  print " hello exec python"
  
• 　　output:
  
  
  sayHi
  __builtins__
  __file__
  __package__
  Person
  Second
  __name__
  __doc__
  Hi , yourname
  Hi
  this is method2
  hello exec python　　
  
  　　from http://hi.baidu.com/zhouhanqing/blog/item/75b6134f2bddd91cb2de051a.html edited some of code
  
  
• 　　some extra info , try look at the following code test in python :
  
  
  
  {'__builtins__': , '__name__': '__main__', '__doc__': None, '__package__': None}
  >>> globals()
  {'__builtins__': , '__name__': '__main__', '__doc__': None, '__package__': None}
  >>> execfile("/home/dengwei/python_test/cpp/1.py")
  hello exec python
  >>> execfile("~/python_test/cpp/1.py")
  Traceback (most recent call last):
    File "", line 1, in
  IOError: [Errno 2] No such file or directory: '~/python_test/cpp/1.py'　　Now we know
  
  
  
  
  • 1.locals()
    
  • 2.globals()
    
  • 3.how to exec a python file (in python)
    
  • 4.we knows exec a python file should specify it's absolute path