cbits
cbits
High-performance BitVector for Python.
Description
cbits implements a powerful bit vector type in C that is accessible via a Python API. It stores bits contiguously in memory and minimizes overhead compared to a list of Boolean values. Core operations such as setting, clearing, flipping and counting bits run in constant or near-constant time per word, making it ideal for extensive bit manipulation.
Installation
pip install cbits
Quick Start
from cbits import BitVector
# Create a 64-bit vector
bv = BitVector(64)
# Set bits, clear, flip, query
bv.set(3)
bv.clear(3)
bv.flip(0)
print(bv.get(0)) # → True or False
print(len(bv), bv.bits)
# Negative indexing
bv.set(-1)
print(bv.get(63))
# Boolean test & rank
print(bool(bv))
print(bv.rank(32)) # count of set bits up to index 32
# Copy & deepcopy
import copy
bv2 = bv.copy()
bv3 = copy.deepcopy(bv)
# Bitwise operations
a.set(0); a.set(2)
b.set(1); b.set(2)
print((a & b)[0], (a | b)[0], (a ^ b)[0], (~a)[0])
# Sequence & iteration
bv[5] = True
print(bv[5])
print([i for i, bit in enumerate(bv) if bit])
# Slicing
sv = bv[2:10] # positions 2..9
print([sv.get(i) for i in range(len(sv))])
sv2 = bv[:5] # first five bits
sv3 = bv[5:] # bits from 5 to end
sv4 = bv[::2] # every other bit
sv_rev = bv[::-1] # reversed vector
print([sv4.get(i) for i in range(len(sv4))])
print([sv_rev.get(i) for i in range(len(sv_rev))])
# Slice assignment from iterables or BitVector
bv[0:4] = [True, False, True, False]
print([bv.get(i) for i in range(4)])
bv[4:8] = BitVector(4) # assign via another BitVector
print([bv.get(i) for i in range(4, 8)])
# Negative-step assignment
bv[9:5:-1] = (i % 2 == 0 for i in range(4))
print([bv.get(i) for i in range(9, 5, -1)])
# Contains
a.set(0); a.set(2); a.set(5) # 10100100
b.set(0); b.set(3) # 1001
print(b in a)
API Reference
Class: BitVector
class BitVector:
def __init__(self, size: int)
@property
def bits(self) -> int
def get(self, index: int) -> bool
def set(self, index: int) -> None
def clear(self, index: int) -> None
def flip(self, index: int) -> None
def rank(self, index: int) -> int
def copy(self) -> BitVector
def __copy__(self) -> BitVector
def __deepcopy__(self, memo) -> BitVector
# Sequence protocol
def __len__(self) -> int
# Single-index access
def __getitem__(self, index: int) -> bool
def __setitem__(self, index: int, value: bool) -> None
# Slicing access & assignment
def __getiten(self, s: slice) -> BitVector
def __setitem(self, s: slice, value: Iterable[bool]) -> None
def __contains__(self, other: BitVector) -> bool
def __iter__(self) -> Iterator[bool]
# Numeric & bitwise protocol
def __and__(self, other: BitVector) -> BitVector
def __iand__(self, other: BitVector) -> BitVector
def __or__(self, other: BitVector) -> BitVector
def __ior__(self, other: BitVector) -> BitVector
def __xor__(self, other: BitVector) -> BitVector
def __ixor__(self, other: BitVector) -> BitVector
def __invert__(self) -> BitVector
def __bool__(self) -> bool
def __repr__(self) -> str
def __str__(self) -> str
License
Apache License 2.0 See LICENSE for details.
