CODEWITHSUNDEEP
pythonpython-2.7
nickexists
nickexists

Reputation: 573

Interpreting bytes received through serial port

In attempting to communicate with a stepper motor controller over a serial port with pyserial I am receiving something like this as a response '/0\x03\r\n'.

I need to be able to convert the '\x03' byte to binary, the part that has me confused is that and '\x03' is considered a single character of the string so I can't do anything like: '\x03'[2:] to get '03'.

How can I convert '\x03' to something usable such as: 00000011 or '03'?

Upvotes: 1

Views: 465

Answers (2)

Martijn Pieters
Martijn Pieters

Reputation: 1122022

\x03 is Python's way of telling you that there is one byte at that part of the string that has a hexadecimal value of 03, which is not a printable character. The first two characters are printable (hex 2F and hex 30, respectively, ASCII characters / and 0) so Python used the ASCII characters they correspond with.

You can use ord() to turn that into an integer:

>>> ord('\x03')
3

You could use the bin() function, or the format() function to turn that integer into a binary representation, with the format() function being the more flexible and versatile option:

>>> bin(3)
'0b11'
>>> format(3, 'b')
'11'
>>> format(3, '08b')
'00000011'

Upvotes: 4

Kevin
Kevin

Reputation: 76194

Try using ord to get each character's numerical value.

>>> s = '/0\x03\r\n'
>>> [ord(c) for c in s]
[47, 48, 3, 13, 10]
>>> [ord(c) for c in s][2]
3

Upvotes: 0

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