python中是否允许字符指针？

Question

我使用的是基于C++的库，返回类型是char指针。我从Python调用这个C++函数。你知道吗

>我的问题是，我能删除从Python中分配的C++函数中的内存吗？你知道吗

Python代码

    lib.TagGetName.restype = c_char_p
    lib.TagGetName.argtypes=[c_int]
    data = 1
    cmt = (b"this is comment for Voltage")
    result = lib.TagGetName(data)

Python输出

Kernel process terminated for restart. (0)
Python 3.4.3 (v3.4.3:9b73f1c3e601, Feb 24 2015, 22:43:06) on Windows (32 bits).
This is the IEP interpreter.
Type 'help' for help, type '?' for a list of *magic* commands.

运行脚本：“D:\QTDev\测试.py““

1
SELECT sTagName FROM TagDataInfo where iTagId = 1;
Return value--> b'Voltage\xfd\xfd\xfd\xfd\xdd`\x18x'

print ("Return value-->" , result)

C++函数代码

USE_MATH char* TagGetName(int iTagId)
{

    char* cName;
    //string cName = "";
    sqlite3_stmt               *stmtCreate = NULL;
    sqlite3                     *m_pdbObj;

    cout<<iTagId<<endl;
   if (sqlite3_open_v2("D:\\QTDev\\forPythonDLL\\Neha_Test_Use\\TagData", &m_pdbObj, SQLITE_OPEN_READWRITE, NULL) != SQLITE_OK)
    {
        return cName;
    }

   char cQuery[1024] = {0};
   sprintf(cQuery,"SELECT sTagName FROM TagDataInfo where iTagId = %d;",iTagId);
cout<<cQuery<<endl;

    if (sqlite3_prepare_v2(m_pdbObj, cQuery, -1, &stmtCreate, 0) == SQLITE_OK)
        {
            sqlite3_step(stmtCreate);
            if(sqlite3_column_text(stmtCreate, 0))
            {

                cName = new char[strlen((char*)sqlite3_column_text(stmtCreate, 0))+1];
                memset(cName,0x00,(strlen((char*)sqlite3_column_text(stmtCreate, 0))+1));
                memcpy(cName,(char*)sqlite3_column_text(stmtCreate, 0),strlen((char*)sqlite3_column_text(stmtCreate, 0)));
                cout<<"Cname="<<cName<<endl;
                cout<<"Database Name="<<(char*)sqlite3_column_text(stmtCreate, 0)<<endl;
            }
            sqlite3_finalize(stmtCreate);
        }
        else 
        {
            return cName; 
        }

    sqlite3_exec(m_pdbObj, "COMMIT", 0, 0, 0);
    return cName;
}

Answer 1

在Python中，不能删除在C++中分配的内存。 您将不得不从C++中导出另一个函数，它将只打包For（）/Delphi调用，并从Python调用它。你知道吗

作为一个旁白，请记住Python正在使用UTF-16，C++可能使用UTF-8，并且需要一些字符串转换（cType可以正确地执行）