如何传递python列表地址

Question

我想把c++代码转换成python。 我用SWIG创建了一个python模块来访问c++类。在

现在我想把下面的c++代码传递给Python

C++ +<

#define LEVEL 3
  double thre[LEVEL] = { 1.0l, 1.0e+2, 1.0e+5 };
  GradedDouble gd(LEVEL, thre);
  gd.avg(thre);

我需要把上面的代码转换成python

< P> C++构造函数用于生成Python模块

^{pr2}$

SWIG接口文件

/*文件：example.i*/

%module example
%include typemaps.i
%apply double * INPUT { double *}
%apply double * INPUT { double *buf };

%{
#include "Item.h"
#include "GradedComplex.h"
#include "GradedDouble.h"
void avg(double *buf);
%}

%include <std_string.i>
%include <std_complex.i>
%include "Item.h"
%include "GradedComplex.h"
%include "GradedDouble.h"
%template(Int) Item<int>;
%template(Double) Item<double>;
%template(Complex) Item<std::complex<double> >;

python模块函数示例

class GradedDouble(_object):
    __swig_setmethods__ = {}
    __setattr__ = lambda self, name, value: _swig_setattr(self, GradedDouble, name, value)
    __swig_getmethods__ = {}
    __getattr__ = lambda self, name: _swig_getattr(self, GradedDouble, name)
    __repr__ = _swig_repr
    def __init__(self, *args): 
        this = _example.new_GradedDouble(*args)
        try: self.this.append(this)
        except: self.this = this
    __swig_destroy__ = _example.delete_GradedDouble
    __del__ = lambda self : None;
    def push(self, *args): return _example.GradedDouble_push(self, *args)
    def avg(self, *args): return _example.GradedDouble_avg(self, *args)
GradedDouble_swigregister = _example.GradedDouble_swigregister
GradedDouble_swigregister(GradedDouble)

如何转换？在

Answer 1

另一种方法是使用swigcpointer和carrays。示例代码如下：

接口文件：

%module example
%include "cpointer.i"
%{
#include "Item.h"
#include "GradedDouble.h"
extern void avg(double *buf);
%}
%pointer_class(double, doublep);

%include "carrays.i"
%array_class(double, doubleArray);
%include <std_string.i>
%include "Item.h"
%include "GradedDouble.h"
%template(Double) Item<double>;

Python代码：

^{pr2}$

这对我有用

Answer 2

在SWIG中，使用raw double*和length作为接口比较困难。您需要为参数对编写一个typemap，它可以智能地读取给定大小的数组。更容易使用SWIG的内置向量支持。在

示例，支持显示：

等级二倍。i

%module GradedDouble

%{
#include "GradedDouble.h"
%}

%include <std_vector.i>
%include <std_string.i>
%template(DoubleVector) std::vector<double>;
%rename(__repr__) ToString;
%include "GradedDouble.h"

等级二倍.h

^{pr2}$

输出

>>> import GradedDouble as gd
>>> x=gd.GradedDouble([1.2,3.4,5.6])
>>> x
GradedDouble( 1.2 3.4 5.6 )