TypeError: Odd-length string when decoding hex string

Question

I've made sure the string is stripped and I still get the odd-length string issue. Can someone please tell me what I'm doing wrong?

>>> toSend = "FF F9 FF 00 00 FA FF F7 FF F4 FF F6 FF F7 FF F6 FF FD FF 05 00 03 00 06 00 05 00 04 00 06 00 06 00 03 00 FB FF 02 00 0B"
>>> toSend.decode("hex")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/encodings/hex_codec.py", line 42, in hex_decode
    output = binascii.a2b_hex(input)
TypeError: Odd-length string
>>> 

Answer 1

The spaces in the string are confusing the decode method. Your code will work if you remove them:

>>> toSend = "FF F9 FF 00 00 FA FF F7 FF F4 FF F6 FF F7 FF F6 FF FD FF 05 00 03 00 06 00 05 00 04 00 06 00 06 00 03 00 FB FF 02 00 0B"
>>> toSend.replace(' ', '').decode('hex')
'\xff\xf9\xff\x00\x00\xfa\xff\xf7\xff\xf4\xff\xf6\xff\xf7\xff\xf6\xff\xfd\xff\x05\x00\x03\x00\x06\x00\x05\x00\x04\x00\x06\x00\x06\x00\x03\x00\xfb\xff\x02\x00\x0b'
>>>

Or, if you must have them, use str.join and a list comprehension:

>>> toSend = "FF F9 FF 00 00 FA FF F7 FF F4 FF F6 FF F7 FF F6 FF FD FF 05 00 03 00 06 00 05 00 04 00 06 00 06 00 03 00 FB FF 02 00 0B"
>>> ' '.join([x.decode('hex') for x in toSend.split()])
'\xff \xf9 \xff \x00 \x00 \xfa \xff \xf7 \xff \xf4 \xff \xf6 \xff \xf7 \xff \xf6 \xff \xfd \xff \x05 \x00 \x03 \x00 \x06 \x00 \x05 \x00 \x04 \x00 \x06 \x00 \x06 \x00 \x03 \x00 \xfb \xff \x02 \x00 \x0b'
>>>