如何将Python字符串传递给C++；（外部C）功能

我有q.cpp

#include <string>
#include <iostream>

extern "C" {

int isNExist (std::string* sequence) {
    std::cout << sequence << std::endl;
    // here I want to process input string and return some int value
    return 0;
}

}

打开命令：

g++ -c -fPIC q.cpp -o q.o
g++ -shared -Wl,-soname,mylib.so -o mylib.so  q.o

当我运行（32位）

python q.py

时，它会返回一个错误：

Traceback (most recent call last):
File "q.py", line 27, in <module>
print(lib.isNExist(string))
OSError: exception: access violation reading 0x43544741

它只传递并打印第一个字符（'H'），但我想传递整个字符串。我该怎么办

编辑2:

---

在cpp中，如果我在isNEsixt函数中传递字符串，它将正确地打印整个字符串，并且

string\u type

是

，因此我假设我在Python代码的结果行中遗漏了一些内容。注释是用python代码编写的

#include <string>
#include <iostream>

extern "C" {

int isNExist (char* sequence) {
    std::cout << sequence << std::endl;
    return 0;
}

---

q.cpp

文件应该保持我的示例中的状态。注释是用python代码编写的

#include <string>
#include <iostream>

extern "C" {

int isNExist (char* sequence) {
    std::cout << sequence << std::endl;
    return 0;
}

from ctypes import cdll, c_char_p, c_char, c_float, c_int,c_wchar_p, POINTER

lib = cdll.LoadLibrary('mylib.so')


# send strings to c function
lib.isNExist.argtypes = [POINTER(c_char_p)]
lib.isNExist.restype = c_int
s = "Hello world!".encode("UTF-8")
string_length = len(s)
string_type = c_char_p*string_length
#print(string_type)
result = lib.isNExist(string_type(*s))

#include <string>
#include <iostream>

extern "C" {

int isNExist (char* sequence) {
    std::cout << sequence << std::endl;
    return 0;
}

from ctypes import cdll, c_char_p, c_char, c_float, c_int,c_wchar_p,addressof, create_string_buffer,POINTER

# connect to .so
lib = cdll.LoadLibrary('mylib.so')

# set data types of arguments of cpp function
lib.isNExist.argtypes = [c_char_p]

# set result data type
lib.isNExist.restype = c_int

# string I want to pass to the function
s = "Hello world!".encode("UTF-8")

# create buffer that will pass my string to cpp function
buff = create_string_buffer(s)

# passing buff to function
result = lib.isNExist(buff)