Python interfacing with C library – How to have a null c pointer
Question:
I have the following old c code.
const char *c[3];
c[0] = "ABC";
c[1] = "EFG";
c[2] = 0;
c_function(c);
Now, I need to use Python to call old c function. I have the following code.
c_names = (c_char_p * 3)()
c_names[0] = "ABC";
c_names[1] = "EFG";
// c[2] = 0??
libc = CDLL("c_library.dll")
libc.c_function(c_names)
May I know what is the Python equivalent for c[2] = 0;?
Answers:
None and 0 both work:
>>> import ctypes
>>> x=ctypes.c_char_p(0)
>>> x
c_char_p(None)
>>> x=ctypes.c_char_p(None)
>>> x
c_char_p(None)
I have the following old c code.
const char *c[3];
c[0] = "ABC";
c[1] = "EFG";
c[2] = 0;
c_function(c);
Now, I need to use Python to call old c function. I have the following code.
c_names = (c_char_p * 3)()
c_names[0] = "ABC";
c_names[1] = "EFG";
// c[2] = 0??
libc = CDLL("c_library.dll")
libc.c_function(c_names)
May I know what is the Python equivalent for c[2] = 0;?
None and 0 both work:
>>> import ctypes
>>> x=ctypes.c_char_p(0)
>>> x
c_char_p(None)
>>> x=ctypes.c_char_p(None)
>>> x
c_char_p(None)