使用ctypes在Python中访问c_char_p_Array_256

Question

我有一个原生的 Python 桥接代码，它可以和一些 C 语言代码进行交互，这些 C 代码会返回一个指向数组的指针（这个数组是由结构体组成的）。这个结构体里面包含了一些字符数组（也就是字符串）。那么，我该如何将 c_char_p_Array_NNN 转换成真正的 Python 字符串呢？

typedef struct td_Group
{
    unsigned int group_id;
    char groupname[256];
    char date_created[32];
    char date_modified[32];
    unsigned int user_modified;
    unsigned int user_created;
} Group;

int getGroups(LIBmanager *, Group **);

############# python code below: 
class Group(Structure):
    _fields_ = [("group_id", c_uint),
                ("groupname", c_char_p*256),
                ("date_created", c_char_p*32),
                ("date_modified", c_char_p*32),
                ("user_modified", c_uint),
                ("user_created", c_uint)]


def somefunc():
    myGroups = c_void_p()
    count = libnativetest.getGroups( nativePointer, byref(myGroups) )
    print "got " + str(count) + " groups!!"
    myCastedGroups = cast( myGroups, POINTER(Group*count) )
    for x in range(0,count):
        theGroup = cast( myCastedGroups[x], POINTER(Group) )
        theGroupName = theGroup.contents.groupname 
        ### Now how do I access theGroupName as a python string?
        # it is a c_char_p_Array_256 presently

Answer 1

这里的类型应该是 c_char*256，而不是 c_char_p*256，因为它是一个 char[256]，而不是 char *[256]。

string_at(theGroupName, sizeof(theGroupName))