BitFields

A generic bitfield is a single byte primitive used for extracting bit values from a byte.

Bit values can be retrieved or set using the get_bit(idx) and set_bit(idx, val) methods respectively.

bf = BitField()
bf.set_bit(0, 1)
bf.set_bit(1, True)
bf.get_bit(0)

The BitField class also support getting/setting bits by indexing on an instance.

bf = BitField()
bf[2] = 1
bf[3] = True

Data can be accessed directly via the .data attribute.

bf = BitField()
bf.data = b"\xFF"

Custom BitFields

A custom BitField enables several unique features not available with a generic BitField.

1. The BitField class internally supports multiple bytes. The length of a BitField class can be adjusted by specifying a byte_length class attribute.

2. Individual bits can be named through the use of the BitPos typed class attributes. Adding these attributes provides an additional method for accessing bit values.

from byteclasses.primitives import BitField, BitPos

class MyBitField(ByteField):
    """A two byte bit field with two named bit."""

    byte_length = 2

    first = BitPos(0)
    middle = BitPos(8, bit_width = 4)
    last = BitPos(15)

bv = MyBitField()
bv.first = 1
bv.middle = 0b1010
bv.last = True