It would be great if the documentation of c_char_p
(http://docs.python.org/library/ctypes.html#ctypes.c_char_p) could be
reformulated as follows (would have saved me quite some time):

class ctypes.c_char_p¶
    Represents the C char * datatype when it points a zero-terminated
string. For a general character pointer that may also point to binary
data, POINTER(c_char) must be used. The constructor accepts an integer
address, or a string.