如何根据指针地址获取指针内容

我使用ctypes调用dll来读取存储区域的内容。但它返回一个无符号字符指针,我想得到指针的内容。我该怎么做?

from ctypes import *

c = WinDLL("FT_ET99_API.dll")
hwnd = c_void_p()
c.et_OpenToken(byref(hwnd), c_char_p('53E00FD8'), c_int(1))
c.et_Verify(hwnd, c_int(0), c_char_p('35316D69696C616E'))
f = c.et_Read
f.argtypes = c_void_p, c_int, c_int, POINTER(c_char_p)
f.restype = None
txt = c_char_p()
f(hwnd, 1, 34, byref(txt))
（What should I do next?）

et_Read（ 

ET_HANDLE hHandle(in),

WORD offset(in), 

int Len(in), 

unsigned char* pucReadBuf(out) 

）