python调用c++ ctype list传数组或者返回数组的方法
示例1:
pycallclass.cpp:
#include <iostream> using namespace std; typedef unsigned char BYTE; #define MAX_COUNT 20 struct tagOutCardResult_py { BYTE cbCardCount; BYTE cbResultCard1; BYTE cbResultCard2; BYTE cbResultCard3; BYTE cbResultCard4; BYTE cbResultCard5; BYTE cbResultCard6; BYTE cbResultCard7; BYTE cbResultCard8; BYTE cbResultCard9; BYTE cbResultCard10; BYTE cbResultCard11; BYTE cbResultCard12; BYTE cbResultCard13; BYTE cbResultCard14; BYTE cbResultCard15; BYTE cbResultCard16; BYTE cbResultCard17; BYTE cbResultCard18; BYTE cbResultCard19; BYTE cbResultCard20; }; struct tagOutCardResult { BYTE cbCardCount; BYTE cbResultCard[MAX_COUNT]; void clear() { cbCardCount = 0; for (int nIdx = 0;nIdx < MAX_COUNT;++nIdx) { cbResultCard[nIdx] = 0; } } void topy(tagOutCardResult_py* ppy) { cout<<"topy function begin"<<endl; ppy->cbCardCount = cbCardCount; cout<<"topy function 1"<<endl; ppy->cbResultCard1 = cbResultCard[1 - 1]; cout<<"topy function 2"<<endl; ppy->cbResultCard2 = cbResultCard[2 - 1]; ppy->cbResultCard3 = cbResultCard[3 - 1]; ppy->cbResultCard4 = cbResultCard[4 - 1]; ppy->cbResultCard5 = cbResultCard[5 - 1]; ppy->cbResultCard6 = cbResultCard[6 - 1]; ppy->cbResultCard7 = cbResultCard[7 - 1]; ppy->cbResultCard8 = cbResultCard[8 - 1]; ppy->cbResultCard9 = cbResultCard[9 - 1]; ppy->cbResultCard10 = cbResultCard[10 - 1]; ppy->cbResultCard11 = cbResultCard[11 - 1]; ppy->cbResultCard12 = cbResultCard[12 - 1]; ppy->cbResultCard13 = cbResultCard[13 - 1]; ppy->cbResultCard14 = cbResultCard[14 - 1]; ppy->cbResultCard15 = cbResultCard[15 - 1]; ppy->cbResultCard16 = cbResultCard[16 - 1]; ppy->cbResultCard17 = cbResultCard[17 - 1]; ppy->cbResultCard18 = cbResultCard[18 - 1]; ppy->cbResultCard19 = cbResultCard[19 - 1]; ppy->cbResultCard20 = cbResultCard[20 - 1]; cout<<"topy function end"<<endl; } }; class TestLib { public: void display(tagOutCardResult& ret); }; void TestLib::display(tagOutCardResult& ret) { ret.cbCardCount = 3; ret.cbResultCard[0] = 1; ret.cbResultCard[1] = 50; ret.cbResultCard[2] = 100; cout<<"First display aaa "; cout<<"hello "; cout<<"world "; } extern "C" { TestLib oGameLogic; void display(tagOutCardResult_py* ret_py) { tagOutCardResult oRet; oGameLogic.display(oRet); cout<<"before topy"<<endl; oRet.topy(ret_py); cout<<"after topy"<<endl; cout<<"in cpp:ret_py->cbCardCount:"<<ret_py->cbCardCount<<endl; cout<<"in cpp:ret_py->cbResultCard1:"<<ret_py->cbResultCard1<<endl; cout<<" this:" << ret_py << endl; } }
编译脚本:
g++ -o libpycallclass.so -shared -fPIC pycallclass.cpp -I/usr/include/python2.6 -L/usr/lib64/python2.6/config
Game.py调用部分。类声明:
import ctypes class tagOutCardResult_py(ctypes.Structure): _fields_ = [("cbCardCount", ctypes.c_ubyte), \ ("cbResultCard1", ctypes.c_ubyte), \ ("cbResultCard2", ctypes.c_ubyte), \ ("cbResultCard3", ctypes.c_ubyte), \ ("cbResultCard4", ctypes.c_ubyte), \ ("cbResultCard5", ctypes.c_ubyte), \ ("cbResultCard6", ctypes.c_ubyte), \ ("cbResultCard7", ctypes.c_ubyte), \ ("cbResultCard8", ctypes.c_ubyte), \ ("cbResultCard9", ctypes.c_ubyte), \ ("cbResultCard10", ctypes.c_ubyte), \ ("cbResultCard11", ctypes.c_ubyte), \ ("cbResultCard12", ctypes.c_ubyte), \ ("cbResultCard13", ctypes.c_ubyte), \ ("cbResultCard14", ctypes.c_ubyte), \ ("cbResultCard15", ctypes.c_ubyte), \ ("cbResultCard16", ctypes.c_ubyte), \ ("cbResultCard17", ctypes.c_ubyte), \ ("cbResultCard18", ctypes.c_ubyte), \ ("cbResultCard19", ctypes.c_ubyte), \ ("cbResultCard20", ctypes.c_ubyte)]
Game.py调用部分。具体调用:
import ctypes so = ctypes.cdll.LoadLibrary lib = so("./libpycallclass.so") ERROR_MSG('display(\)') ret = tagOutCardResult_py(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) ERROR_MSG("before lib.display(ctypes.byref(ret))") lib.display(ctypes.byref(ret)) ERROR_MSG("after lib.display(ctypes.byref(ret))") ERROR_MSG('#######################################################################################') ERROR_MSG(ret) ERROR_MSG(ret.cbCardCount) ERROR_MSG(ret.cbResultCard1) ERROR_MSG(ret.cbResultCard2) ERROR_MSG(ret.cbResultCard3) ERROR_MSG(type(ret))
传入一个结构体,使用引用返回,回到python中打印出来结果是对的。
这样就可以传入,可以传出了。
示例1end#########################################################################
示例2:
pycallclass.cpp:
#include <iostream> using namespace std; typedef unsigned char BYTE; #define MAX_COUNT 20 #if defined(WIN32)||defined(WINDOWS) #define DLL_EXPORT __declspec(dllexport) #else #define DLL_EXPORT #endif struct ByteArray_20 { BYTE e1; BYTE e2; BYTE e3; BYTE e4; BYTE e5; BYTE e6; BYTE e7; BYTE e8; BYTE e9; BYTE e10; BYTE e11; BYTE e12; BYTE e13; BYTE e14; BYTE e15; BYTE e16; BYTE e17; BYTE e18; BYTE e19; BYTE e20; }; struct ByteArray_20_3 { ByteArray_20 e1; ByteArray_20 e2; ByteArray_20 e3; }; struct ByteArrayNew_20_3 { BYTE e[3][20]; }; class TestLib { public: void LogicFunc(ByteArray_20_3& ret); void LogicFuncNew(ByteArrayNew_20_3& ret); }; void TestLib::LogicFunc(ByteArray_20_3& ret) { ret.e1.e1 = 3; ret.e1.e2 = 1; ret.e1.e3 = 50; ret.e2.e1 = 100; ret.e2.e2 = 200; ret.e2.e3 = 20; cout<<"TestLib::LogicFunc"<<endl; } void TestLib::LogicFuncNew(ByteArrayNew_20_3& ret) { ret.e[0][0] = 31; ret.e[0][1] = 11; ret.e[0][2] = 51; ret.e[1][0] = 101; ret.e[1][1] = 201; ret.e[1][2] = 21; cout << "TestLib::LogicFuncNew" << endl; } extern "C" { TestLib oGameLogic; void DLL_EXPORT display(ByteArray_20_3* pret) { cout<<"cpp display func begin"<<endl; oGameLogic.LogicFunc(*pret); cout<<"cpp display func end"<<endl; } void DLL_EXPORT display2(ByteArrayNew_20_3* pret) { cout << "cpp display2 func begin" << endl; oGameLogic.LogicFuncNew(*pret); cout << "cpp display2 func end" << endl; } }
pycallclass.py:
import ctypes def ERROR_MSG(str): print str class ByteArray_20(ctypes.Structure): _fields_ = [\ ("e1", ctypes.c_ubyte), \ ("e2", ctypes.c_ubyte), \ ("e3", ctypes.c_ubyte), \ ("e4", ctypes.c_ubyte), \ ("e5", ctypes.c_ubyte), \ ("e6", ctypes.c_ubyte), \ ("e7", ctypes.c_ubyte), \ ("e8", ctypes.c_ubyte), \ ("e9", ctypes.c_ubyte), \ ("e10", ctypes.c_ubyte), \ ("e11", ctypes.c_ubyte), \ ("e12", ctypes.c_ubyte), \ ("e13", ctypes.c_ubyte), \ ("e14", ctypes.c_ubyte), \ ("e15", ctypes.c_ubyte), \ ("e16", ctypes.c_ubyte), \ ("e17", ctypes.c_ubyte), \ ("e18", ctypes.c_ubyte), \ ("e19", ctypes.c_ubyte), \ ("e20", ctypes.c_ubyte)] class ByteArray_20_3(ctypes.Structure): _fields_ = [\ ("e1", ByteArray_20), \ ("e2", ByteArray_20), \ ("e3", ByteArray_20)] def __init__(self): self.aaa = 123 self.bbb = [1, 2, 3, 4, 5] self.ccc = "alksdfjlasdfjk" def test(self): self.aaa = 123 self.bbb = [1, 2, 3, 4, 5] self.ccc = "alksdfjlasdfjk" self.e1.e1 = 5 self.e1.e2 = 20 so = ctypes.cdll.LoadLibrary lib = so("./libpycallclass.dll") print('display()') ret = ByteArray_20_3() ret.test() ERROR_MSG(ret.e1.e1) ERROR_MSG(ret.e1.e2) print("before lib.display(ctypes.byref(ret))") lib.display(ctypes.byref(ret)) print("after lib.display(ctypes.byref(ret))") print('#######################################################################################') print(ret) ERROR_MSG(ret.e1) ERROR_MSG(ret.e2) ERROR_MSG(ret.e3) ERROR_MSG(ret.e1.e1) ERROR_MSG(ret.e1.e2) ERROR_MSG(ret.e1.e3) ERROR_MSG(ret.e2.e1) ERROR_MSG(ret.e2.e2) ERROR_MSG(ret.e2.e3) ERROR_MSG(type(ret)) print("before lib.display2(ctypes.byref(ret))") lib.display2(ctypes.byref(ret)) print("after lib.display2(ctypes.byref(ret))") print('#######################################################################################') print(ret) ERROR_MSG(ret.e1) ERROR_MSG(ret.e2) ERROR_MSG(ret.e3) ERROR_MSG(ret.e1.e1) ERROR_MSG(ret.e1.e2) ERROR_MSG(ret.e1.e3) ERROR_MSG(ret.e2.e1) ERROR_MSG(ret.e2.e2) ERROR_MSG(ret.e2.e3) ERROR_MSG(type(ret)) ret.test() ERROR_MSG(ret.e1.e1) ERROR_MSG(ret.e1.e2)
g++:
g++ -o libpycallclass.so -shared -fPIC pycallclass.cpp -I/usr/include/python2.6 -L/usr/lib64/python2.6/config
windows:
新建一个DLL工程,把pycallclass.cpp加进去,编译成DLL就OK了。
千万注意python的运行时是32位的还是64位的,DLL或者SO必须和它对应。
python类可以嵌套使用,继承ctypes.Structure,部分成员是_fields_里定义的,部分成员在__init__里定义,这样的类也可以ctypes.byref(self)传进c++去,传的是指针,传入传出就都OK了。
注意示例2中ByteArrayNew_20_3的用法,python中是定义了20个变量,c++中是直接一个二维数组。内存结构是一致的,所以可以直接这样使用。注意类型和长度必须一致,否则可能会内存访问越界。
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