cpyberry / pybitfield

A library that makes it easy to handle bitfields with python

pybitfield

A library that makes it easy to handle bitfield with python

Requirements

• python 3.6, 3.7, 3.8, 3.9

Installation

pip install pybitfield

Usage

When you construct a bitfield with 5 elements, do as follows.

In this case, information up to 5 bits can be stored.

Unless otherwise specified, all bits are 0.

You can use BitOrder enumerator class to specify the bit order.

If you want to specify little endian, you should specify BitOrder.little in the bit_order argument.

from pybitfield import Bitfield, BitOrder


number_of_element = 5
bitfield = Bitfield(number_of_element, bit_order=BitOrder.big)

If you want to set the bit, do as follows.

Since the index is zero based, the bitfield stored when running this code is 01111.

This is the case for big endian.

bitfield.set_bit(0)
bitfield.set_bit(1)
bitfield.set_bit(2)
bitfield.set_bit(3)

# Since the number of elements is 5 and the index is zero-based, a total of 5 index from 0 to 4 can be specified.
# bitfield.set_bit(5)

This code remove the 1st and 3rd bits.

This result is 00101

bitfield.remove_bit(1)
bitfield.remove_bit(3)

You can use is_bit() to make sure the bit is set.

bitfield.is_bit(1)  # return False
bitfield.is_bit(2)  # return True

If you want to convert bitfield to list type, you can use get_bit_list().

The index of bitfield and the index of list correspond.

0 is converted to False, 1 is converted to True.

If you specify little endian, the converted list is reversed.

bitfield.get_bit_list()

# [True, False, True, False, False]

If you want to reverse bitfield, you can use swap_bitfield().

The argument represents the bit length.

If you call the method with no arguments, the number of elements in the bitfield is applied to the bit length of the return value.

bitfield.swap_bitfield()
# 20
# 0b10100

bitfield.swap_bitfield(8)
# 160
# 0b10100000

bitfield.swap_bitfield(10)
# 640
# 0b1010000000

If you want to convert bitfield to bytes type, you can use get_bitfield_bytes().

If the number of elements in the bitfield is not a multiple of 8, the smallest byte length that can represent it will be applied.

In this case, the number of elements in the bitfield is 5, so the byte length of 1 is applied.

bitfield.get_bitfield_bytes()
# b'\x05'
# 0b00000101

If you specify little endian, the a returned array of bytes will be reversed.

bitfield.get_bitfield_bytes()
# b'\xa0'
# 0b10100000

Founder

• cpyberry

  email: [e-mail]