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說完看着這樣一個問題：ctypes的：用C malloc分配結構的暴露陣列
ctypes: How do I define an array of a structure as a field of another structure?
現在我想實現我的版本的解決方案，但在len_a的struct Arr輸出不同於它在C中的設置。我的問題是：什麼是將Parse.arr設置爲python中的一個Arr對象數組的正確方法是什麼？（最初是在C中分配/設置的）？在線self.arr = cast(byref(self.parse.arr),POINTER(Arr*n)).contentspylink.py上有明顯的錯誤。
clink.c
#include <stdio.h>
#include <stdlib.h>
#define SIZE 10
struct Arr {
int len_a;
};
struct Parse {
struct Arr* arr;
int len_arr;
};
struct Parse* C_new_domain(void) {
int i = 0;
struct Parse* parse = malloc(sizeof(struct Parse));
parse->arr = malloc(SIZE*sizeof(struct Arr));
for (i=0 ; i<SIZE ; i++) {
parse->arr[i].len_a = i;
}
parse->len_arr = SIZE;
return parse;
}
void C_end_program(struct Parse* parse) {
free(parse->arr);
free(parse);
return;
}
pylink.py
import sys
from ctypes import *
_lib = cdll.LoadLibrary('./libclink.so')
class Arr(Structure):
def __init__(self, obj, name=""):
self.obj = obj
_fields_ = [("len_a", c_int)]
class Parse(Structure):
def __init__(self, obj, name=""):
self.obj = obj
_fields_ = [("arr", POINTER(Arr)),
("len_arr", c_int)]
class Domain(object):
domain = POINTER(Parse)
parse = None
arr = None
_lib.C_new_domain.argtype = None
_lib.C_new_domain.restype = POINTER(Parse)
_lib.C_end_program.argtype = POINTER(Parse)
def __init__(self):
self.domain = _lib.C_new_domain()
self.parse = self.domain.contents
n = self.parse.len_arr
self.arr = cast(byref(self.parse.arr),POINTER(Arr*n)).contents
def end(self):
_lib.C_end_program(self.domain)
if __name__ == '__main__':
domain = Domain()
for count, array in enumerate(domain.arr):
print "[Hoping this is %d] --> array[%d].len_a is %d"%(count, count, array.len_a)
domain.end()
輸出
[Hoping this is 0] --> array[0].len_a is 25023216
[Hoping this is 1] --> array[1].len_a is 0
[Hoping this is 2] --> array[2].len_a is 10
[Hoping this is 3] --> array[3].len_a is 32512
[Hoping this is 4] --> array[4].len_a is 14962
[Hoping this is 5] --> array[5].len_a is 0
[Hoping this is 6] --> array[6].len_a is 33
[Hoping this is 7] --> array[7].len_a is 0
[Hoping this is 8] --> array[8].len_a is 10
[Hoping this is 9] --> array[9].len_a is 0