传递Tuple嵌入式Python

Passing Tuple Embedded Python

本文关键字:Python 嵌入式 Tuple 传递      更新时间:2023-10-16

所以我正在编写一个C++应用程序,它使用对Python的嵌入式调用来运行一些计算。我有在指定目录中运行任何脚本的代码,以及在C++应用程序和Python解释器之间传递和返回一个值的代码。

然而,当我试图将多个值作为参数传递给Python时,我遇到了一个问题。以下是我运行Python脚本的代码:

double Script::run_script(string moduleName, string funcName, double *params, 
              int numberOfParams)
{
  PyObject *pName, *pModule, *pDict, *pFunc;
  PyObject *pArgs, *pValue;
  int i;
  // Set aside memory for the path to my scripts to add to sys.path
  char dir[255];
  memset(dir, 0, sizeof(dir));
  /* ********************************************* */
  sprintf(dir, "/home/bmalone/workspace/NumericalAnalysis/Testing"); //Put path into dir
   /* ********************************************* */
  Py_Initialize();
  PyObject *dictModule = PyImport_GetModuleDict();
  PyObject *sys = PyDict_GetItemString(dictModule, "sys");
  // Sys NULL?
  if (sys == NULL)
    {
      cerr << "Cannot find sys in dict!" << endl;
      return -1;
    }
  dictModule = PyModule_GetDict(sys);
  PyObject *path = PyDict_GetItemString(dictModule, "path");
  PyObject *pPath = PyUnicode_FromString(dir);
  PyList_Append(path, pPath);
  if (pPath);
    //cerr << "PATH > " << PyString_AsString(PyObject_Repr(path)) << endl;
  else
    cerr << "pPath IS NULL" << endl;

  /* Import the module that contains the function/script */
  pModule = PyImport_ImportModule(moduleName.c_str());
  if (pModule);
    //cerr << "pModule ~ " << PyString_AsString(PyObject_Repr(pModule)) << endl;
  else
    cerr << "pModule is NULL!!" << endl;
  //cerr << "Getting dict for argv[1]..." << endl;
  dictModule = PyModule_GetDict(pModule);
  if (dictModule);
    //cerr << "DictModule ~ " << PyString_AsString(PyObject_Repr(dictModule))  << endl;
  else
    cerr << "DictModule is NULL!!" << endl;
  // CALL THE FUNCTION!
  /*
   * argv[1] is the MODULE name, but argv[2] SHOULD BE the function name!
   */
  /* Get a PyObject referencing the function from the module 'pModule' */
  //pFunc = PyObject_GetAttrString(pModule, funcName.c_str());
  pFunc = PyDict_GetItemString(dictModule, funcName.c_str());
  if (pFunc)
    {
      PyObject *objRep = PyObject_Repr(pFunc);
      const char* str = PyString_AsString(objRep);
      cerr << "Func is a real boy, too! - " << str  << endl;
    }
  else
    cerr << "pFunc is NULL!" << endl;
  /* Setup PyArgs */
  pArgs = PyTuple_New(numberOfParams);
  // Add the data as doubles
  cerr << "<parameters> ~ params size is " << numberOfParams  << endl;
  for (int i = 0; i < numberOfParams; i++)
    {
      if (params)
    {
      /* **************************** */
      //pValue = PyDouble_AsDouble(params[i]);
      pValue = PyFloat_FromDouble(params[i]);
      /* **************************** */
      cerr << " " << params[i] << endl;
      PyObject* objRep = PyObject_Repr(pValue);
      const char* strRep = PyString_AsString(objRep);
      cerr << ">> pValue = " << strRep << endl;
      PyTuple_SetItem(pArgs, i, pValue);
    }
      else
    break;
    }
  cerr << "<Module> - " << moduleName << ", is null: " << (pModule == NULL) << endl;
  cerr << "<Function> - " << funcName << ", is null: " << (pFunc == NULL) << endl;
  // Get the retun value
  cerr << "<Calling Function>" << endl;
  //pValue = PyObject_CallFunction(pFunc, "f", 15.0); // **WORKS**
  pValue = PyObject_CallObject(pFunc, pArgs); // **WORKS**
  //pValue = PyObject_CallObject(pFunc, NULL);
  //pValue = PyEval_CallObject(pFunc, NULL);
  //pValue = PyObject_CallFunction(pFunc, NULL);
  //pValue = PyObject_CallObject(pFunc, args);
  //pValue = PyEval_CallObject(pFunc, args);
  //cerr << "ANSWER ---> " << PyFloat_AsDouble(pValue) << endl;
  return PyFloat_AsDouble(pValue);
  Py_Finalize();
}

编辑:在我最初的帖子中,我做了一个我忘记做过的更改,这是一个阻止任何脚本运行的错误。上面的代码正确地运行任何脚本,除外)它只有在pArgs具有--1--元素时才有效。每当我试图传递多个元素,甚至传递到同一个脚本以便打印出来时,该脚本甚至从未运行过。但如果它只是1,那么它就完美地工作了。

我似乎不知道我做错了什么,把一个以上的参数传递给我的脚本。这是我试图从C++(适用于1个参数的脚本)运行的脚本:

#!/usr/bin/python
'''
Created on Jul 12, 2012
@author: bmalone
'''
import sys

def doubleTwo(x, y):
    print str(sys.argv)
    print "Can haz doubling?n"

if __name__ == '__main__':
    doubleTwo()

任何帮助都将不胜感激!

我发现了我遇到的问题。在我的函数中,我试图访问命令行参数,而在编写函数时,我指定它们是传递参数的——我没有这样做。

将来,对于任何发现嵌入式Python有问题的人来说,我发现Python-C API中有一个非常有用的错误部分,如果PyErr_Occurred()为真,PyErr_Print()将错误打印到stderr。

我要么需要修复传递的实际参数,要么(我最终使用的是)在使用"PyObject_CallObject"调用函数并通过在sys.argv.

上进行索引来访问Python中需要的参数之前使用"PySys_SetArgv"