使用python调用C++函数

我正在try 为一个在C++中实现的函数构建python包装器，该函数接受2d vector并返回2d vector.我正在try 调整this的代码以满足我的需要.

Input matrix shape: (n*2)  
Output matrix shape: (n*2)

I think there is an issue with code.i file but not really sure what exactly is the issue.
If there are any other libraries which can achieve this that works as well. I just need to call the c++ function from python.
Here is complete reproducible example: Google Colab
My files:
code.cpp:

#include <vector>
#include "geomutils.h"
#include "code.h"

using namespace std;

vector< vector<double> > computeConvexHull(vector< vector<double> > i_matrix){
  Polygon custompts, customhull;
  for (int r = 0; r < i_matrix.size(); r++){
    custompts.push_back(Point(i_matrix[r][0], i_matrix[r][1]));
  }
  computeConvexHull(custompts, customhull);
  vector< vector<double> > res;
  for(int i = 0;i < customhull.size();i ++) {
        res[i][0] = customhull[i].x;
        res[i][1] = customhull[i].y;
  }
  return res;
}

geomutils.cpp:

#include "geomutils.h"

#include <iostream>

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <boost/geometry/geometries/adapted/boost_tuple.hpp>

BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian)


void computeConvexHull(Polygon &pts, Polygon &chull) {
    chull.clear();
    if(pts.size() == 1) {
        chull.push_back(pts[0]);
        chull.push_back(pts[0]);
        return;
    } else if(pts.size() == 2) {
        chull.push_back(pts[0]);
        chull.push_back(pts[1]);
        chull.push_back(pts[0]);
        return;
    }

    typedef boost::tuple<double, double> point;
    typedef boost::geometry::model::multi_point<point> mpoints;
    typedef boost::geometry::model::polygon<point> polygon;

    mpoints mpts;

    for(int i = 0;i < pts.size();i ++) {
        boost::geometry::append(mpts,point(pts[i].x,pts[i].y));
    }
    polygon hull;

    // Polygon is closed
    boost::geometry::convex_hull(mpts, hull);
    for(auto pt : hull.outer()) {
        chull.push_back(Point(pt.get<0>(), pt.get<1>()));
    }
}

geomutils.h:

#ifndef GEOMUTILS_H
#define GEOMUTILS_H

#include <vector>

struct Point {
    double x,y;

    Point(){}
    Point(double x, double y):x(x),y(y){}
};

typedef std::vector<Point> Polygon;

void computeConvexHull(Polygon &pts, Polygon &chull);

#endif // GEOMUTILS_H

code.i:

%module code
%{
#include "code.h"
#include "geomutils.h"
%}
%include "std_vector.i"
namespace std {

  /* On a side note, the names VecDouble and VecVecdouble can be changed, but the order of first the inner vector matters! */
  %template(VecDouble) vector< vector<double> >;
  %template(VecVecdouble) vector< vector<double> >;
}

%include "code.h"

代码使用一个名为boost的外部库.我try 生成包装器的方式如下:

g++ -c -fPIC code.cpp geomutils.cpp

swig -c++ -python code.i

g++ -c -fPIC code_wrap.cxx  -I/usr/include/python3.7 -I/usr/lib/python3.7

The first two commands run without giving any error but the third code gives me an error.
The Error is too long to post in the question. But the error can be reproduced using code link. Update 1:
After trying the changes suggested in answer 1 and running the following commands the code compiles but nothing happens when I try to run the c++ code from python. The code is updated in the same link. "test.py" is a simple python code that calls the computeConvexHull function.
Commands:

g++ -c -fPIC code.cpp geomutils.cpp
swig -c++ -python code.i
g++ -c -fPIC code_wrap.cxx  -I/usr/include/python3.7 -I/usr/lib/python3.7
g++ -shared -Wl,-soname,_code.so -o _code.so code.o geomutils.o code_wrap.o
python test.py