c++ - Are character pointer allowed in python? -


i using c++ based library return type char pointer. calling c++ function within python.

my question can delete memory allocated in c++ function python?

python code 

    lib.taggetname.restype = c_char_p     lib.taggetname.argtypes=[c_int]     data = 1     cmt = (b"this comment voltage")     result = lib.taggetname(data)

python output

kernel process terminated restart. (0) python 3.4.3 (v3.4.3:9b73f1c3e601, feb 24 2015, 22:43:06) on windows (32 bits). iep interpreter. type 'help' help, type '?' list of *magic* commands.

running script: "d:\qtdev\test.py"

1 select stagname tagdatainfo itagid = 1; return value--> b'voltage\xfd\xfd\xfd\xfd\xdd`\x18x'  print ("return value-->" , result)

c++ function code

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 tagdatainfo 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; }

in python can't delete memory being allocated in c++. have export function c++ wrap free()/delete call, , call python.

as aside, remember python using utf-16 , c++ may using utf-8, , string conversion needed ( ctype can )


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