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 )


-

Comments

Post a Comment

Popular posts from this blog

c# - Binding a comma separated list to a List<int> in asp.net web api -

the default binder in web api expecst http://url.com/webapi/report/?pageids=3243&pageids=2365 to bind public ihttpactionresult report(list<int> pageids){ // exciting webapi code} i wish bind http://url.com/webapi/report/?pageids=3243,2365 as running out of space in url get . i have created class public class commaseparatedmodelbinder : system.web.http.modelbinding.imodelbinder { public bool bindmodel(httpactioncontext actioncontext, modelbindingcontext bindingcontext) { //binding in here } } and registered in webapiconfig.cs var provider = new simplemodelbinderprovider( typeof(list<int>), new commaseparatedmodelbinder()); config.services.insert(typeof(modelbinderprovider), 0, provider); i have altered method signature use model binder so public ihttpactionresult report( [modelbinder] list<int> pageids){ // exciting webapi code} however break point in binder not being ...
Read more

how to prompt save As Box in Excel Interlop c# MVC 4 -

i want export excel sheet using excel interloop... i have datatable convert excel sheet... now there way save file using save dialogue box in mvc 4 here code public string datatabletoexcel(datatable dt, string htmlheading, string key) { try { microsoft.office.interop.excel.application excel; microsoft.office.interop.excel.workbook excelworkbook; microsoft.office.interop.excel.worksheet excelsheet; microsoft.office.interop.excel.range excelcellrange; excel = new microsoft.office.interop.excel.application(); excel.visible = false; excel.displayalerts = false; excelworkbook = excel.workbooks.add(type.missing); excelsheet = (microsoft.office.interop.excel.worksheet)excelworkbook.activesheet; excelsheet.name = "sheet1"; dataset ...
Read more

xslt 1.0 - How to access or retrieve mets content of an item from another item? -

my use case have item has link in item. example, item 123456789/152 has metadata field dc.relation.hasversion=123456789/717 . within item view of 123456789/152 , how can retrieve values of metadata of 123456789/717 ? example, want retrieve dc.language.iso value of 123456789/717 123456789/152 . i looked @ related items feature in dspace don't know how metadata displayed in related items list pulled items in list. i using dspace version 5.3 mirage 2 theme . edit based on schweerelos answer, below actual code. using custom metadata field dc.relation.languageversion . basically, want link other version instead of displaying value, display dc.language.iso of other version in item-view.xsl . i've incorporated answer of schweerelos question in code just displaying value of dc.relation.languageversion . sample values of dc.relation.languageversion 10665.1/9843 ; 10665.1/9844 ie not complete uri handle. thanks in advance! actual code <xsl:template name=...
Read more