Python中的SWIG C ++矢量访问

Question

This may be a noob question but here it goes. I have wrapped a 3d vector into a python module using SWIG. Everything has compiled and I can import the module and perform actions with it. I can't seem to figure out how to access my vector in python to store and change values in it. How do I store and change my vector values in python. My code is below and was written to test if the algorithm stl works with SWIG. It does seem to work but I need to be able to put values into my vector with python.

header.h

 #ifndef HEADER_H_INCLUDED

 #define HEADER_H_INCLUDED

 #include <vector>

 using namespace std;

 struct myStruct{

 int vecd1, vecd2, vecd3;

 vector<vector<vector<double> > >vec3d;

 void vecSizer();
 void deleteDuplicates();
 double vecSize();
 void run();
 };

 #endif // HEADER_H_INCLUDED

main.cpp

 #include "header.h"
 #include <vector>
 #include <algorithm>

 void myStruct::vecSizer()
 {
     vec3d.resize(vecd1);

     for(int i = 0; i < vec3d.size(); i++)
     {
         vec3d[i].resize(vecd2);

         for(int j = 0; j < vec3d[i].size(); j++)
         {
             vec3d[i][j].resize(vecd3);
         }
     }
 }

 void myStruct::deleteDuplicates()
 {
     vector<vector<vector<double> > >::iterator it;
     sort(vec3d.begin(),vec3d.end());
     it = unique(vec3d.begin(),vec3d.end());
     vec3d.resize(distance(vec3d.begin(), it));
 }

 double myStruct::vecSize()
 {
     return vec3d.size();
 }

 void myStruct::run()
 {
     vecSizer();
     deleteDuplicates();
     vecSize();
 }

from the terminal (Ubuntu)

 import test #import the SWIG generated module
 x = test.myStruct() #create an instance of myStruct
 x.vecSize() #run vecSize() should be 0 since vector dimensions are not initialized
 0.0 
 x.vec3d #see if vec3d exists and is of the correct type
 <Swig Object of type 'vector< vector< vector< double > > > *' at       0x7fe6a483c8d0>

Thanks in advance!

Answer 1

It turns out that vectors are converted to immutable python objects when the wrapper/interface is generated. So in short you cannot modify wrapped c++ vectors from python.