Boost Python 实现C调用python错误解决方法

古城微笑少年丶 2022-08-03 05:17 254阅读 0赞

由于Boost Python跟不上Python版本更新，如下方法调用可能产生TypeError: 'NoneType' object does not support item assignment异常。

Boost Python文档中例子可能产生异常。

Py\_Initialize();  
object main\_module = import("\_\_main\_\_");  
object main\_dict = main\_module.attr("\_\_dict\_\_");  
try\{  
   object result = exec("result = 5 + 5",main\_dict);  
   int five\_squared = extract<int>(main\_dict\["result"\]);  
   cout<<"extract value : "<<five\_squared<<endl;  
   cin>>ij;  
\}  
    catch(error\_already\_set)\{  
        PyErr\_Print();  
        cin>>ij;  
    \}  
  
可以如下方法解决

Py\_Initialize();  
object main\_module = import("\_\_main\_\_");  
object main\_dict = main\_module.attr("\_\_dict\_\_");  
try\{  
    handle<> ignored((PyRun\_String(  
  
        "result = 5 \*\* 2"  
  
        , Py\_file\_input  
        , main\_dict.ptr()  
        , main\_dict.ptr())  
    ));  
   int five\_squared = extract<int>(main\_dict\["result"\]);  
   cout<<"extract value : "<<five\_squared<<endl;  
   cin>>ij;  
\}  
    catch(error\_already\_set)\{  
        PyErr\_Print();  
        cin>>ij;  
    \}

Boost Python中执行表达式函数也可以正常运行。

Py\_Initialize();  
object main\_module = import("\_\_main\_\_");  
object main\_dict = main\_module.attr("\_\_dict\_\_");  
try\{  
   object result = eval("5 + 5",main\_dict);  
   int five\_squared = extract<int>(result);  
   cout<<"extract value : "<<five\_squared<<endl;  
   cin>>ij;  
\}  
    catch(error\_already\_set)\{  
        PyErr\_Print();  
        cin>>ij;  
    \}