有没有办法在 Python 和 C 之间传递结构
Is there a way to pass structure between Python and C
我正在使用 Python API 用 C 编写程序。
Python会将输入（结构）传递给C程序，C程序会根据输入执行一些操作。
谁能告诉我是否可以在 Python 和 C 之间传递结构。如果可以，请告诉我如何传递它。
我使用 SWIG 接口在 C 和 Python 之间传递值。示例程序运行良好（使用变量）。我已经添加了带有结构的代码，但我不确定它的代码格式。如果我做错了什么，请纠正我。我是 Python 和 C 的新手。我到处搜索使用 SWIG 的传递结构，我无法得到任何正确答案。
逻辑是从Python中取出输入值，然后在c中进行乘法运算，return得到Python的值。
Sample.c
#include<stdio.h>
#include "sample.h"
struct info sample;
int getstruct (struct info sample);
int getstruct (struct info sample) {
int i = 0;
int j = 0;
int k = 0;
int l = 0;
i = 2 * sample.i;
j = 2 * sample.j;
k = 2 * sample.k;
l = 2 * sample.l;
sample.i = i;
sample.j = j;
sample.k = k;
sample.l = l;
return(&sample);
}
sample.h
struct info
{
int i;
int j;
int k;
int l;
};
extern struct info data;
sample.i
%module sample
%{
#include "sample.h"
%}
%include "sample.h"
sample.py (automatically generated by SWIG)
# This file was automatically generated by SWIG (http://www.swig.org).
# Version 2.0.11
#
# Do not make changes to this file unless you know what you are doing--modify
# the SWIG interface file instead.
from sys import version_info
if version_info >= (2,6,0):
def swig_import_helper():
from os.path import dirname
import imp
fp = None
try:
fp, pathname, description = imp.find_module('_sample', [dirname(__file__)])
except ImportError:
import _sample
return _sample
if fp is not None:
try:
_mod = imp.load_module('_sample', fp, pathname, description)
finally:
fp.close()
return _mod
_sample = swig_import_helper()
del swig_import_helper
else:
import _sample
del version_info
try:
_swig_property = property
except NameError:
pass # Python < 2.2 doesn't have 'property'.
def _swig_setattr_nondynamic(self,class_type,name,value,static=1):
if (name == "thisown"): return self.this.own(value)
if (name == "this"):
if type(value).__name__ == 'SwigPyObject':
self.__dict__[name] = value
return
method = class_type.__swig_setmethods__.get(name,None)
if method: return method(self,value)
if (not static):
self.__dict__[name] = value
else:
raise AttributeError("You cannot add attributes to %s" % self)
def _swig_setattr(self,class_type,name,value):
return _swig_setattr_nondynamic(self,class_type,name,value,0)
def _swig_getattr(self,class_type,name):
if (name == "thisown"): return self.this.own()
method = class_type.__swig_getmethods__.get(name,None)
if method: return method(self)
raise AttributeError(name)
def _swig_repr(self):
try: strthis = "proxy of " + self.this.__repr__()
except: strthis = ""
return "<%s.%s; %s >" % (self.__class__.__module__, self.__class__.__name__, strthis,)
try:
_object = object
_newclass = 1
except AttributeError:
class _object : pass
_newclass = 0
class info(_object):
__swig_setmethods__ = {}
__setattr__ = lambda self, name, value: _swig_setattr(self, info, name, value)
__swig_getmethods__ = {}
__getattr__ = lambda self, name: _swig_getattr(self, info, name)
__repr__ = _swig_repr
__swig_setmethods__["i"] = _sample.info_i_set
__swig_getmethods__["i"] = _sample.info_i_get
if _newclass:i = _swig_property(_sample.info_i_get, _sample.info_i_set)
__swig_setmethods__["j"] = _sample.info_j_set
__swig_getmethods__["j"] = _sample.info_j_get
if _newclass:j = _swig_property(_sample.info_j_get, _sample.info_j_set)
__swig_setmethods__["k"] = _sample.info_k_set
__swig_getmethods__["k"] = _sample.info_k_get
if _newclass:k = _swig_property(_sample.info_k_get, _sample.info_k_set)
__swig_setmethods__["l"] = _sample.info_l_set
__swig_getmethods__["l"] = _sample.info_l_get
if _newclass:l = _swig_property(_sample.info_l_get, _sample.info_l_set)
def __init__(self):
this = _sample.new_info()
try: self.this.append(this)
except: self.this = this
__swig_destroy__ = _sample.delete_info
__del__ = lambda self : None;
info_swigregister = _sample.info_swigregister
info_swigregister(info)
# This file is compatible with both classic and new-style classes.
cvar = _sample.cvar
Error message:
Python 2.7.6 (default, Mar 22 2014, 22:59:56)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sample
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "sample.py", line 28, in <module>
_sample = swig_import_helper()
File "sample.py", line 24, in swig_import_helper
_mod = imp.load_module('_sample', fp, pathname, description)
ImportError: ./_sample.so: undefined symbol: data
>>>
Commands used:
swig -python sample.i
gcc -fPIC -c sample.c sample_wrap.c -I/usr/include/python2.7
ld -shared sample.o sample_wrap.o -o _sample.so
您可以查看swig。
我自己使用它并且可以确认它工作得很好。查看 tutorial 以获得 python 示例。
正在执行以下代码：
头文件：
#include<stdio.h>
typedef struct
{
int i;
int j;
int k;
int l;
} MyStruct;
extern MyStruct sample;
extern int getstruct (MyStruct sample);
C档
#include "example.h"
int getstruct (MyStruct sample) {
int i = 0;
int j = 0;
int k = 0;
int l = 0;
i = 2 * sample.i;
j = 2 * sample.j;
k = 2 * sample.k;
l = 2 * sample.l;
sample.i = i;
sample.j = j;
sample.k = k;
sample.l = l;
return(&sample);
}
接口文件：
%module example
%{
#include "example.h"
%}
%include "example.h"
编译和link个文件：
$ swig -python example.i
$ gcc -fPIC -c example.c example_wrap.c -I/usr/include/python2.7
$ gcc -lpython -shared example.o example_wrap.o -o _example.so
现在 python:
>>> import example
>>> a = example.MyStruct
>>> dir(a)
['__class__', '__del__', '__delattr__', '__dict__', '__doc__',
'__format__', '__getattr__', '__getattribute__', '__hash__',
'__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__',
'__repr__', '__setattr__', '__sizeof__', '__str__',
'__subclasshook__', '__swig_destroy__', '__swig_getmethods__',
'__swig_setmethods__', '__weakref__', 'i', 'j', 'k', 'l', 'this']
>>> a.i = 1
>>> a.j = 1
>>> a.k = 1
>>> a.l = 1
>>> example.getstruct(a)
1605330080
我不确定结果是什么（也许是样本地址？）。
PS:看了Lee Daniel Crocker的回复，值得考虑
我正在使用 Python API 用 C 编写程序。
Python会将输入（结构）传递给C程序，C程序会根据输入执行一些操作。
谁能告诉我是否可以在 Python 和 C 之间传递结构。如果可以，请告诉我如何传递它。
我使用 SWIG 接口在 C 和 Python 之间传递值。示例程序运行良好（使用变量）。我已经添加了带有结构的代码，但我不确定它的代码格式。如果我做错了什么，请纠正我。我是 Python 和 C 的新手。我到处搜索使用 SWIG 的传递结构，我无法得到任何正确答案。
逻辑是从Python中取出输入值，然后在c中进行乘法运算，return得到Python的值。
Sample.c
#include<stdio.h>
#include "sample.h"
struct info sample;
int getstruct (struct info sample);
int getstruct (struct info sample) {
int i = 0;
int j = 0;
int k = 0;
int l = 0;
i = 2 * sample.i;
j = 2 * sample.j;
k = 2 * sample.k;
l = 2 * sample.l;
sample.i = i;
sample.j = j;
sample.k = k;
sample.l = l;
return(&sample);
}
sample.h
struct info
{
int i;
int j;
int k;
int l;
};
extern struct info data;
sample.i
%module sample
%{
#include "sample.h"
%}
%include "sample.h"
sample.py (automatically generated by SWIG)
# This file was automatically generated by SWIG (http://www.swig.org).
# Version 2.0.11
#
# Do not make changes to this file unless you know what you are doing--modify
# the SWIG interface file instead.
from sys import version_info
if version_info >= (2,6,0):
def swig_import_helper():
from os.path import dirname
import imp
fp = None
try:
fp, pathname, description = imp.find_module('_sample', [dirname(__file__)])
except ImportError:
import _sample
return _sample
if fp is not None:
try:
_mod = imp.load_module('_sample', fp, pathname, description)
finally:
fp.close()
return _mod
_sample = swig_import_helper()
del swig_import_helper
else:
import _sample
del version_info
try:
_swig_property = property
except NameError:
pass # Python < 2.2 doesn't have 'property'.
def _swig_setattr_nondynamic(self,class_type,name,value,static=1):
if (name == "thisown"): return self.this.own(value)
if (name == "this"):
if type(value).__name__ == 'SwigPyObject':
self.__dict__[name] = value
return
method = class_type.__swig_setmethods__.get(name,None)
if method: return method(self,value)
if (not static):
self.__dict__[name] = value
else:
raise AttributeError("You cannot add attributes to %s" % self)
def _swig_setattr(self,class_type,name,value):
return _swig_setattr_nondynamic(self,class_type,name,value,0)
def _swig_getattr(self,class_type,name):
if (name == "thisown"): return self.this.own()
method = class_type.__swig_getmethods__.get(name,None)
if method: return method(self)
raise AttributeError(name)
def _swig_repr(self):
try: strthis = "proxy of " + self.this.__repr__()
except: strthis = ""
return "<%s.%s; %s >" % (self.__class__.__module__, self.__class__.__name__, strthis,)
try:
_object = object
_newclass = 1
except AttributeError:
class _object : pass
_newclass = 0
class info(_object):
__swig_setmethods__ = {}
__setattr__ = lambda self, name, value: _swig_setattr(self, info, name, value)
__swig_getmethods__ = {}
__getattr__ = lambda self, name: _swig_getattr(self, info, name)
__repr__ = _swig_repr
__swig_setmethods__["i"] = _sample.info_i_set
__swig_getmethods__["i"] = _sample.info_i_get
if _newclass:i = _swig_property(_sample.info_i_get, _sample.info_i_set)
__swig_setmethods__["j"] = _sample.info_j_set
__swig_getmethods__["j"] = _sample.info_j_get
if _newclass:j = _swig_property(_sample.info_j_get, _sample.info_j_set)
__swig_setmethods__["k"] = _sample.info_k_set
__swig_getmethods__["k"] = _sample.info_k_get
if _newclass:k = _swig_property(_sample.info_k_get, _sample.info_k_set)
__swig_setmethods__["l"] = _sample.info_l_set
__swig_getmethods__["l"] = _sample.info_l_get
if _newclass:l = _swig_property(_sample.info_l_get, _sample.info_l_set)
def __init__(self):
this = _sample.new_info()
try: self.this.append(this)
except: self.this = this
__swig_destroy__ = _sample.delete_info
__del__ = lambda self : None;
info_swigregister = _sample.info_swigregister
info_swigregister(info)
# This file is compatible with both classic and new-style classes.
cvar = _sample.cvar
Error message:
Python 2.7.6 (default, Mar 22 2014, 22:59:56)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sample
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "sample.py", line 28, in <module>
_sample = swig_import_helper()
File "sample.py", line 24, in swig_import_helper
_mod = imp.load_module('_sample', fp, pathname, description)
ImportError: ./_sample.so: undefined symbol: data
>>>
Commands used:
swig -python sample.i
gcc -fPIC -c sample.c sample_wrap.c -I/usr/include/python2.7
ld -shared sample.o sample_wrap.o -o _sample.so
您可以查看swig。
我自己使用它并且可以确认它工作得很好。查看 tutorial 以获得 python 示例。
正在执行以下代码：
头文件：
#include<stdio.h>
typedef struct
{
int i;
int j;
int k;
int l;
} MyStruct;
extern MyStruct sample;
extern int getstruct (MyStruct sample);
C档
#include "example.h"
int getstruct (MyStruct sample) {
int i = 0;
int j = 0;
int k = 0;
int l = 0;
i = 2 * sample.i;
j = 2 * sample.j;
k = 2 * sample.k;
l = 2 * sample.l;
sample.i = i;
sample.j = j;
sample.k = k;
sample.l = l;
return(&sample);
}
接口文件：
%module example
%{
#include "example.h"
%}
%include "example.h"
编译和link个文件：
$ swig -python example.i
$ gcc -fPIC -c example.c example_wrap.c -I/usr/include/python2.7
$ gcc -lpython -shared example.o example_wrap.o -o _example.so
现在 python:
>>> import example
>>> a = example.MyStruct
>>> dir(a)
['__class__', '__del__', '__delattr__', '__dict__', '__doc__',
'__format__', '__getattr__', '__getattribute__', '__hash__',
'__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__',
'__repr__', '__setattr__', '__sizeof__', '__str__',
'__subclasshook__', '__swig_destroy__', '__swig_getmethods__',
'__swig_setmethods__', '__weakref__', 'i', 'j', 'k', 'l', 'this']
>>> a.i = 1
>>> a.j = 1
>>> a.k = 1
>>> a.l = 1
>>> example.getstruct(a)
1605330080
我不确定结果是什么（也许是样本地址？）。
PS:看了Lee Daniel Crocker的回复，值得考虑