On Thu, Apr 12, 2018 at 4:20 PM, <jf...@ms4.hinet.net> wrote: > Chris Angelico於 2018年4月12日星期四 UTC+8下午1時31分35秒寫道： >> On Thu, Apr 12, 2018 at 2:16 PM, <jf...@ms4.hinet.net> wrote: >> > This C function returns a buffer which I declared it as a ctypes.c_char_p. >> > The buffer has size 0x10000 bytes long and the valid data may vary from a >> > few bytes to the whole size. >> > >> > In every call I know how much the valid data size is, but I suppose I >> > can't use slice to get it because there may be zero byte in it. What to do? >> > >> >> You suppose? Or have you tested it? >> >> ChrisA > > Yes, I had test it once before. Now, I re-do it again to make sure. After a > call which returns 3 bytes of data, I use len(buf) to check the length and > get the number 24. I can see the first 24 bytes of data by using buf[:30] but > buf[24] will cause an "index out of range" error. I don't know how to see > what the buf[24] exactly is but I suppose it might be a zero byte. >
If you have 24 bytes, they're numbered 0 through 23. So there is no byte at 24. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
