Convert Python byte to "unsigned 8 bit integer"

Question

I am reading in a byte array/list from socket. I want Python to treat the first byte as an "unsigned 8 bit integer". How is it possible to get its integer value as an unsigned 8 bit integer?

Answer 1

Use the struct module.

import struct
value = struct.unpack('B', data[0])[0]

Note that unpack always returns a tuple, even if you're only unpacking one item.

Also, have a look at this SO question.

Answer 2

bytes/bytearray is a sequence of integers. If you just access an element by its index you'll have an integer:

>>> b'abc'
b'abc'
>>> _[0]
97

By their very definition, bytes and bytearrays contain integers in the range(0, 256). So they're "unsigned 8-bit integers".

Answer 3

Another very reasonable and simple option, if you just need the first byte’s integer value, would be something like the following:

value = ord(data[0])

If you want to unpack all of the elements of your received data at once (and they’re not just a homogeneous array), or if you are dealing with multibyte objects like 32-bit integers, then you’ll need to use something like the struct module.