python ctypes 怎么處理函數(shù)返回的一般指針

test.c(動態(tài)庫源代碼)

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[cpp] view plain copy

// 編譯生成動態(tài)庫: gcc -g -fPIC -shared -o libtest.so test.c

#include stdio.h

#include string.h

#include stdlib.h

typedef struct StructPointerTest

{

char name[20];

int age;

}StructPointerTest, *StructPointer;

StructPointer test() // 返回結(jié)構(gòu)體指針

{

StructPointer p = (StructPointer)malloc(sizeof(StructPointerTest));

strcpy(p-name, "Joe");

p-age = 20;

return p;

}

編譯：gcc -g -fPIC -shared -o libtest.so test.c

call.py(python調(diào)用C語言生成的動態(tài)庫):

[python] view plain copy

#!/bin/env python

# coding=UTF-8

from ctypes import *

#python中結(jié)構(gòu)體定義

class StructPointer(Structure):

_fields_ = [("name", c_char * 20), ("age", c_int)]

if __name__ == "__main__":

lib = cdll.LoadLibrary("./libtest.so")

lib.test.restype = POINTER(StructPointer)

p = lib.test()

print "%s: %d" %(p.contents.name, p.contents.age)

最后運(yùn)行結(jié)果：

[plain] view plain copy

[zcm@c_py #112]$make clean

rm -f *.o libtest.so

[zcm@c_py #113]$make

gcc -g -fPIC -shared -o libtest.so test.c

[zcm@c_py #114]$./call.py

Joe: 20

[zcm@c_py #115]$

python使用C函數(shù)返回的指針

int* GrabImage();

int GetPixel(int* image, int x, int y);

void SetPixel(int* image, int x, int y, int color);

python 中callback怎么使用

在計算機(jī)程序設(shè)計中，回調(diào)函數(shù)，或簡稱回調(diào)（Callback），是指通過函數(shù)參數(shù)傳遞到其它代碼的，某一塊可執(zhí)行代碼的引用。這一設(shè)計允許了底層代碼調(diào)用在高層定義的子程序：

例如：

def?my_callback(input):

print?"function?my_callback?was?called?with?%s?input"?%?(input,)

def?caller(input,?func):

func(input)

for?i?in?range(5):

caller(i,?my_callback)

執(zhí)行結(jié)果是：

function?my_callback?was?called?with?0?input

function?my_callback?was?called?with?1?input

function?my_callback?was?called?with?2?input

function?my_callback?was?called?with?3?input

function?my_callback?was?called?with?4?input