类型映射资源并将列表转换为矢量(并返回）

我不知道是否有具体原因，但包含的std_vector.i将输出向量转换为元组而不是列表。如果需要列表，则需要编写自定义类型映射表。

示例(无错误检查(：

%module add_array
%{
#include "add_array.h"
%}
%include <std_vector.i>
%template(vectorInt) std::vector<int>;
// Override the template output typemap with one that returns a list.
// An "out" typemap controls how a value is returned.
// When a function returns std::vector<int> this template will convert it to
// a Python object.  In this case, a PyList.
// 
// Note: PyObject* tmp declares a local variable that will be used by this code snippet.
// Make sure to look at the generated wrapper code and find the add_array_wrap function
// and how this code is integrated into it.
// 
%typemap(out) std::vector<int> (PyObject* tmp) %{
// Allocate a PyList object of the requested size.
// $1 references the first type in the type list (in this case, std::vector<int>)
// and represents the c++ return value of a function that returns
// this type; therefore, we can call methods on that value to get the size.
//
// Note: The elements of the new PyList are null pointers and MUST be
//       populated before returning it to Python.
//
tmp = PyList_New($1.size());
// Populate the PyList.  PyLong_FromLong converts a C++ "long" to a
// Python PyLong object.  PyList_SET_ITEM takes a PyList object (tmp),
// an index (i), and a Python object to put in the list.  This particular
// function *steals* the reference to the Python object, so you don't have to
// Py_DECREF the object to free it later.
//
for(int i = 0; i < $1.size(); ++i)
PyList_SET_ITEM(tmp,i,PyLong_FromLong($1[i]));
// $result is where you assign the Python object that should be returned
// after converting the C++ $1 object.  SWIG_Python_AppendOutput is not
// well-documented, but it appends the return object to an existing
// returned object.  It's most useful for "argout" typemaps where multiple
// output or in/out arguments in C++ can be returned as a tuple of
// return values in Python.  For example, a function like:
//
//     void func(int* pValue1, int* pValue2);
//
// would normally return None ($result = Py_None), but an "argout" typemap
// could *$1 to a PyLong and use SWIG_Python_AppendOutput to add it to
// the result.  The template would be applied twice and you'd get a tuple.
//
$result = SWIG_Python_AppendOutput($result,tmp);
%}
%include "add_array.h"

输出：

>>> import add_array
>>> add_array.add_array([1,2,3],[4,5,6])
[5, 7, 9]

就教程而言，我只读过 SWIG 文档和 C 语言扩展的特定语言文档。 作为文档，它实际上非常好，但你不能只是挑选要阅读的内容。 研究前十几个部分的基础知识，然后跳到特定于语言的部分(例如 Python(。SWIG安装下还有一个示例目录。

引用：

• PyLong_FromLong
• PyList_New
• PyList_SET_ITEM
• std_vector.i

您必须查看SWIG资源以获取有关SWIG_Python_AppendOutput的任何信息。 或者只是谷歌搜索其他人的例子。