This module performs conversions between Python values and C bit field structs represented as Python bytearrays.
Project description
About
This module is intended to have a similar interface as the python struct module, but working on bits instead of primitive data types (char, int, …).
Documentation: http://bitstruct.readthedocs.org/en/latest
Installation
pip install bitstruct
Example usage
See the test suite: https://github.com/eerimoq/bitstruct/blob/master/tests/test_bitstruct.py
A basic example of packing/unpacking four integers:
>>> from bitstruct import *
>>> pack('u1u3u4s16', 1, 2, 3, -4)
bytearray(b'\xa3\xff\xfc')
>>> unpack('u1u3u4s16', bytearray(b'\xa3\xff\xfc'))
(1, 2, 3, -4)
>>> calcsize('u1u3u4s16')
24
The unpacked fields can be named by assigning them to variables or by wrapping the result in a named tuple:
>>> from bitstruct import *
>>> from collections import namedtuple
>>> MyName = namedtuple('myname', [ 'a', 'b', 'c', 'd' ])
>>> unpacked = unpack('u1u3u4s16', bytearray(b'\xa3\xff\xfc'))
>>> myname = MyName(*unpacked)
>>> myname
myname(a=1, b=2, c=3, d=-4)
>>> myname.c
3
An example of packing/unpacking a unsinged integer, a signed integer, a float and a bytearray:
>>> from bitstruct import *
>>> pack('u5s5f32b13', 1, -1, 3.75, bytearray(b'\xff\xff'))
bytearray(b'\x0f\xd0\x1c\x00\x00?\xfe')
>>> unpack('u5s5f32b13', bytearray(b'\x0f\xd0\x1c\x00\x00?\xfe'))
(1, -1, 3.75, bytearray(b'\xff\xf8'))
>>> calcsize('u5s5f32b13')
55
An example of unpacking values from a hexstring and a binary file:
>>> from bitstruct import *
>>> from binascii import *
>>> unpack('s17s13b24', bytearray(unhexlify('0123456789abcdef')))
(582, -3751, bytearray(b'\xe2j\xf3'))
>>> with open("test.bin", "rb") as fin:
... unpack('s17s13b24', bytearray(fin.read(8)))
...
...
(582, -3751, bytearray(b'\xe2j\xf3'))
Change endianness of the data with byteswap(), and then unpack the values:
>>> from bitstruct import *
>>> packed = pack('u1u3u4s16', 1, 2, 3, 1)
>>> unpack('u1u3u4s16', byteswap('12', packed))
(1, 2, 3, 256)
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Source Distribution
Built Distribution
Hashes for bitstruct-1.0.1-py2.py3-none-any.whl
Algorithm | Hash digest | |
---|---|---|
SHA256 | f901be975e9f7e74de70ac13bf2854ec1f1ade6aa254396e0b9627793c021e84 |
|
MD5 | 8a1387a3fb5a58ff08051dd5eab26e06 |
|
BLAKE2b-256 | ba66586d58ae392b128e4a1604f6673731253ab15876770c323d735f506198dc |