如何构建需要cmake的C ++嵌入式Python文件？

问题描述

我创建了一个C ++文件，它有一个应该从Python文件中调用的函数。但是这个C ++文件需要通过cmake构建，因为存在OpenCV依赖项。当我运行主Python文件时，我收到以下错误：

 ImportError：/usr/local/lib/python2.7 /dist-packages/getGender.so：未定义的符号：_ZN2cv3Mat10deallocateEv 

下面是C ++文件getGender.cpp，它具有该功能这将由Python代码调用。

  #include   <   Python.h  >  
   #include     opencv2 / core / core.hpp 
   #include     opencv2 / contrib / contrib.hpp 
   #include     opencv2 / highgui / highgui.hpp 
   #include   <   iostream  >  
   #include   <   fstream  >  
   #include   <   sstream  >  
  
 使用 命名空间 cv; 
 使用 命名空间标准; 
 
  static  Mat norm_0_255（InputArray _src）{
 Mat src = _src.getMat（）; 
  //  创建并返回标准化图像： 
 Mat dst; 
  switch （src.channels（））{
  case   1 ：
 cv :: normalize（_src，dst， 0 ， 255 ，NORM_MINMAX，CV_8UC1）; 
  break ; 
  case   3 ：
 cv :: normalize（_src，dst， 0 ， 255 ，NORM_MINMAX，CV_8UC3）; 
  break ; 
 默认：
 src.copyTo（dst）; 
  break ; 
} 
  return  dst; 
} 
 
 
 
  int  getGender（ const   char  * path）{
 
 
 vector< Mat>图片; 
 
 images.push_back（imread（path， 0 ））; 
 
 Mat testSample = images [ 0 ]; 
 
 Ptr< FaceRecognizer> model1 = createFisherFaceRecognizer（）; 
 
 model1-> load（  fisherfaces.yml）; 
 
  int  predictLabel = model1-> predict（testSample）; 
 
 string result_message = format（ 预测类=％d，predictLabel ）; 
 cout<< result_message<< ENDL; 
 
  return  predictLabel; 
} 
 
  static  PyObject * getGender_wrapper（PyObject * self，PyObject * args）
 {
 
  char  * path; 
 
  return  Py_BuildValue（  i的，getGender（路径））; 
 
} 
 
 
 静态 PyMethodDef genderMethods [] = {{  getGender，getGender_wrapper，METH_VARARGS，  find gender}，
 {NULL，NULL， 0 ，NULL} 
}; 
 
 PyMODINIT_FUNC initxt（）
 {
 Py_InitModule（  getGender ，genderMethods）; 
} 

以下是链接代码的setup.py文件。

 来自 distutils.core  import 设置，扩展
 
 extension_mod =扩展名（  getGender，[  getGender.cpp]）
 
 setup（name =   getGender，ext_modules = [extension_mod]）

我运行命令python setup.py build然后python setup.py install。然后我创建了一个测试文件，如下所示并运行它。那是我收到错误的时候。

  import  getGender 
 gender = \\ text.getGenderWrapper（  / home / kavin / Desktop / actors_cropped / male / a1_200_200.jpg）
 
  print 性别

我认为错误是因为无法立即构建c ++文件getGender.cpp。我通常构建一个cmake文件，以便从这个cpp文件创建exe。在这种情况下，我不知道如何将该cmake文件合并到此。请帮助。

解决方案

I have created a C++ file which has a function that should be called from the Python file. But this C++ file requires to be built through cmake as there are OpenCV dependencies. When I run the main Python file I am getting the following error:

ImportError: /usr/local/lib/python2.7/dist-packages/getGender.so: undefined symbol: _ZN2cv3Mat10deallocateEv

Below is the C++ file,getGender.cpp, that has the function which would be called by Python code.

#include <Python.h>
#include "opencv2/core/core.hpp"
#include "opencv2/contrib/contrib.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
#include <fstream>
#include <sstream>

using namespace cv;
using namespace std;

static Mat norm_0_255(InputArray _src) {
Mat src = _src.getMat();
// Create and return normalized image:
Mat dst;
switch(src.channels()) {
case 1:
    cv::normalize(_src, dst, 0, 255, NORM_MINMAX, CV_8UC1);
    break;
case 3:
    cv::normalize(_src, dst, 0, 255, NORM_MINMAX, CV_8UC3);
    break;
default:
    src.copyTo(dst);
    break;
}
return dst;
}



int getGender(const char *path) {


vector<Mat> images;

images.push_back(imread(path, 0));

 Mat testSample = images[0];

Ptr<FaceRecognizer> model1 = createFisherFaceRecognizer();

model1->load("fisherfaces.yml");

int predictedLabel = model1->predict(testSample);

string result_message = format("Predicted class = %d ",predictedLabel);
cout << result_message << endl;

return predictedLabel;
}

static PyObject *getGender_wrapper(PyObject *self,PyObject *args)
{

char *path;

return Py_BuildValue("i",getGender(path));

}


static PyMethodDef genderMethods[]= {{"getGender",getGender_wrapper,METH_VARARGS,"find gender"},
{NULL,NULL,0,NULL}
};

 PyMODINIT_FUNC initxt()
{
Py_InitModule("getGender",genderMethods);
} 

Below is the setup.py file which links the code.

from distutils.core import setup,Extension

extension_mod=Extension("getGender",["getGender.cpp"])

setup(name="getGender",ext_modules=[extension_mod])

I ran the commands, "python setup.py build" and then "python setup.py install". Then I created a test file as following and ran it. That is when I get the error.

import getGender
   gender=ext.getGenderWrapper("/home/kavin/Desktop/actors_cropped/male/a1_200_200.jpg")

print gender

I think the error is because the c++ file getGender.cpp cannot be built straight away. There is a cmake file I usually build in order to create the exe from this cpp file. In this scenario, I dont know how to incorporate that cmake file into this. Please help.

解决方案

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