SWIG将二维数组类型映射到Python列表

2022-05-28 00:00:00 python arrays char swig c++

这是question的下一个级别。我需要将2D C字符数组强制转换为Python列表。

Python端

device_info = getInfoFromCpp()
print(device_info.angles)
for angle in device_info.angles:
  print("Angel: " + angle)

错误

<Swig Object of type 'char (*)[MaxStringLength]' at 0x000000D8B2710330>
Execution error: 'SwigPyObject' object is not iterable

С++标头

struct DeviceInformation {
  static const int MaxStringLength= 200;
  static const int MaxNumberOfAngles= 5;

  char serialNumber[MaxStringLength];
  char angles[MaxNumberOfAngles][MaxStringLength];
};

基于@MarkTolonen的answer我尝试了以下类型映射,但没有结果。

// %typemap(out) char*[ANY] %{
// %typemap(out) char (*)[ANY] %{
%typemap(out) char [ANY][ANY] %{
    PyObject *pyArray = PyList_New(5);
    for (uint8_t i = 0; i < 5; ++i) {
        PyObject *pyString = PyString_FromString(reinterpret_cast<char*>($1[i]));
        PyList_SetItem(pyArray, i, pyString);
    }
    $result = pyArray;
%}

解决方案

您的代码为我工作,但以下是问题注释和工作示例中提到的一些更正:

Test.i

%module test

// This works for any size of 2d char array assuming it contains
// UTF-8-encoded, null-terminated strings (no error checking!)
%typemap(out) char [ANY][ANY] %{
    $result = PyList_New($1_dim0);
    for (Py_ssize_t i = 0; i < $1_dim0; ++i) {
        PyList_SET_ITEM($result, i, PyUnicode_FromString($1[i]));
    }
%}

%inline %{
struct DeviceInformation {
  static const int MaxStringLength= 200;
  static const int MaxNumberOfAngles= 5;

  char serialNumber[MaxStringLength];
  char angles[MaxNumberOfAngles][MaxStringLength];
};

// test function
DeviceInformation getInfoFromCpp() {
    return {"serialnumber",{"angle1","angle2","angle3","angle4","angle5"}};
}
%}

演示:

>>> import test
>>> x=test.getInfoFromCpp()
>>> x.serialNumber
'serialnumber'
>>> x.angles
['angle1', 'angle2', 'angle3', 'angle4', 'angle5']

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