[Python-Dev] C struct for Str( ) (original) (raw)

Eddy Quicksall Eddy at Quicksall.com
Fri Jan 15 18:31:23 EST 2016

I want to fill an Str() string from a C function. But I think I am using the wrong structure (PyBytesObject). I have written a C function to dump the Python class but as you can see the structure I'm using does not match the data in the class.

Can someone please tell me the correct structure:

--------- Python snip --------- class _vendorRecord_2: vendorListNumber = str() vendorNumber = str() vendorName = str('x' * 20)

vendorRecord_2 = _vendorRecord_2()

print(len(vendorRecord_2.vendorName)) print(vendorRecord_2.vendorName + '|') XBaseDump_PythonString(py_object(vendorRecord_2.vendorName))

--------- C function -------- #define MS_NO_COREDLL #undef _DEBUG #include <W:\Python-3.5.1\Include\python.h> DSI_DLL void CALL_TYPE XBaseDump_PythonString( PyBytesObject *pBytesObject ) { printf( "ob_size = %d, ob_shash = %X, ob_sval = %s\n", pBytesObject->ob_base.ob_size, pBytesObject->ob_shash, pBytesObject->ob_sval ); printf( "offsetof(ob_size) = %d, offsetof(ob_sval) = %d\n", offsetof( PyBytesObject, ob_base.ob_size ), offsetof( PyBytesObject, ob_sval ) ); printf( "sizeof(PyBytesObject) = %d\n", sizeof(PyBytesObject) ); DsmDumpBytes( pBytesObject, 32 ); }

-------- output ------------ 20 xxxxxxxxxxxxxxxxxxxx| ob_size = 20, ob_shash = 70768D53, ob_sval = σsci offsetof(ob_size) = 8, offsetof(ob_sval) = 16 sizeof(PyBytesObject) = 20 0000: 03 00 00 00 60 B0 DC 1D 14 00 00 00 53 8D 76 70 ....-........... 0016: E5 73 63 69 00 00 00 00 78 78 78 78 78 78 78 78 V...............

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