我覺得會(huì)受到限制的，因?yàn)閏_char_p是遵循c字符串標(biāo)準(zhǔn)的，會(huì)以NULL為結(jié)束。下面的代碼只輸出hello,也許真要傳遞內(nèi)嵌NULL的，只能靠編寫python擴(kuò)展了，也很簡(jiǎn)單的，用swig。

from ctypes import *
import struct 

example=cdll.LoadLibrary("example.dll")
s=create_string_buffer('hello\x00world')
example.test.restype=c_char_p
example.test.argtypes = [c_char_p]
r=example.test(s) #("hello\x00world")
print r

Python是解釋性語(yǔ)言, 底層就是用c實(shí)現(xiàn)的, 所以用python調(diào)用C是很容易的, 下面就總結(jié)一下各種調(diào)用的方法, 給出例子, 所有例子都在ubuntu9.10, python2.6下試過(guò)
1. Python 調(diào)用 C (base)
想在python中調(diào)用c函數(shù), 如這兒的fact
#include <Python.h>

int fact(int n)
{
if (n <= 1)
return 1;
else
return n * fact(n - 1);
}

PyObject* wrap_fact(PyObject* self, PyObject* args)
{
int n, result;

if (! PyArg_ParseTuple(args, "i:fact", &n))
return NULL;
result = fact(n);
return Py_BuildValue("i", result);
}

static PyMethodDef exampleMethods[] =
{
{"fact", wrap_fact, METH_VARARGS, "Caculate N!"},
{NULL, NULL}
};

void initexample()
{
PyObject* m;
m = Py_InitModule("example", exampleMethods);
}

把這段代碼存為wrapper.c, 編成so庫(kù),
gcc -fPIC wrapper.c -o example.so -shared -I/usr/include/python2.6 -I/usr/lib/python2.6/config

然后在有此so庫(kù)的目錄, 進(jìn)入python, 可以如下使用
import example
example.fact(4)

2. Python 調(diào)用 C++ (base)
在python中調(diào)用C++類成員函數(shù), 如下調(diào)用TestFact類中的fact函數(shù),
#include <Python.h>

class TestFact{
public:
TestFact(){};
~TestFact(){};
int fact(int n);
};

int TestFact::fact(int n)
{
if (n <= 1)
return 1;
else
return n * (n - 1);
}

int fact(int n)
{
TestFact t;
return t.fact(n);
}
PyObject* wrap_fact(PyObject* self, PyObject* args)
{
int n, result;

if (! PyArg_ParseTuple(args, "i:fact", &n))
return NULL;
result = fact(n);
return Py_BuildValue("i", result);
}

static PyMethodDef exampleMethods[] =
{
{"fact", wrap_fact, METH_VARARGS, "Caculate N!"},
{NULL, NULL}
};

extern "C" //不加會(huì)導(dǎo)致找不到initexample
void initexample()
{
PyObject* m;
m = Py_InitModule("example", exampleMethods);
}

把這段代碼存為wrapper.cpp, 編成so庫(kù),
g++ -fPIC wrapper.cpp -o example.so -shared -I/usr/include/python2.6 -I/usr/lib/python2.6/config

然后在有此so庫(kù)的目錄, 進(jìn)入python, 可以如下使用
import example
example.fact(4)

3. Python 調(diào)用 C++ (Boost.Python)
Boost庫(kù)是非常強(qiáng)大的庫(kù), 其中的python庫(kù)可以用來(lái)封裝c++被python調(diào)用, 功能比較強(qiáng)大, 不但可以封裝函數(shù)還能封裝類, 類成員.
首先在ubuntu下安裝boost.python, apt-get install libboost-python-dev
#include <boost/python.hpp>
char const* greet()
{
return "hello, world";
}

BOOST_PYTHON_MODULE(hello)
{
using namespace boost::python;
def("greet", greet);
}

把代碼存為hello.cpp, 編譯成so庫(kù)
g++ hello.cpp -o hello.so -shared -I/usr/include/python2.5 -I/usr/lib/python2.5/config -lboost_python-gcc42-mt-1_34_1

此處python路徑設(shè)為你的python路徑, 并且必須加-lboost_python-gcc42-mt-1_34_1, 這個(gè)庫(kù)名不一定是這個(gè), 去/user/lib查

然后在有此so庫(kù)的目錄, 進(jìn)入python, 可以如下使用
>>> import hello
>>> hello.greet()
'hello, world'

4. python 調(diào)用 c++ (ctypes)
ctypes is an advanced ffi (Foreign Function Interface) package for Python 2.3 and higher. In Python 2.5 it is already included.
ctypes allows to call functions in dlls/shared libraries and has extensive facilities to create, access and manipulate simple and complicated C data types in Python - in other words: wrap libraries in pure Python. It is even possible to implement C callback functions in pure Python.

#include <Python.h>

class TestFact{
public:
TestFact(){};
~TestFact(){};
int fact(int n);
};

int TestFact::fact(int n)
{
if (n <= 1)
return 1;
else
return n * (n - 1);
}

extern "C"
int fact(int n)
{
TestFact t;
return t.fact(n);
}
將代碼存為wrapper.cpp不用寫python接口封裝, 直接編譯成so庫(kù),
g++ -fPIC wrapper.cpp -o example.so -shared -I/usr/include/python2.6 -I/usr/lib/python2.6/config

進(jìn)入python, 可以如下使用
>>> import ctypes
>>> pdll = ctypes.CDLL('/home/ubuntu/tmp/example.so')
>>> pdll.fact(4)

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