---
id: bitarray-hardbyte
version: "2.3.8"
license: PSF
license_treatment: permissive
maintenance: active
---

# bitarray-hardbyte — efficient arrays of booleans -- C extension

License: permissive · Maintenance: active · Downloads: 93.8K/mo

## What it is and what it does

bitarray-hardbyte is a C extension that provides a memory-efficient array type for storing boolean values. Eight bits are packed into a single byte, making it far more compact than a Python list of booleans. The library supports both big-endian and little-endian bit ordering, allowing fine-grained control over how bits map to bytes—important when working with binary protocols, file formats, or memory-mapped data.

The package behaves like a standard Python sequence: you can slice, extend, iterate, and apply bitwise operations (&, |, ^, ~, <<, >>) directly on bitarray objects. It includes utility functions for encoding/decoding variable-length prefix codes, converting to hexadecimal, creating Huffman codes, and serialization. All functionality is implemented in C for speed, and the library supports the buffer protocol for zero-copy interoperability with other binary data structures like numpy arrays.

Use it for:

- Storing large sets of boolean flags or bit masks where memory efficiency is critical.
- Implementing Bloom filters, bitmaps, or other bit-level data structures.
- Working with binary file formats or network protocols that require precise bit-level manipulation.
- Creating Huffman codes or other variable-length prefix codes for compression.
- Interfacing with memory-mapped files or C libraries that expect raw bit-level data.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Provides an efficient C-backed array type for storing and manipulating sequences of boolean values, with support for bitwise operations, slicing, and endianness control.

Yes, if you need memory-efficient boolean storage or bit-level operations. The package is mature, actively maintained, permissively licensed, and has no known vulnerabilities. Install friction is moderate due to C compilation, but precompiled wheels cover most common platforms. Not necessary for typical Python applications that don't require bit-level manipulation or extreme memory optimization.

## Install

pip install bitarray-hardbyte
uv add bitarray-hardbyte
poetry add bitarray-hardbyte

## Installing bitarray-hardbyte

Before you install: Medium install friction due to C compilation requirement, but precompiled wheels are available for common platforms (macOS, Linux, Windows, multiple architectures). Maintenance is active with recent commits and a stable release history since 2019.

License in practice: Licensed under the Python Software Foundation License (PSF), a permissive license that allows commercial and private use with minimal restrictions.

Quickstart:

pip install bitarray-hardbyte

from bitarray import bitarray
a = bitarray()
a.append(1)
a.extend([1, 0])
print(a)  # bitarray('110')
print(a.count(1))  # 2

Requires a C compiler if installing from source; precompiled wheels available for Python 3.6–3.10 on macOS, Linux (x86_64, i686), and Windows.

Verify before relying:

- Whether bitarray-hardbyte is a maintained fork or variant of the original bitarray package and how it differs functionally.
- Current Python 3.11+ support status, given that friction evidence shows wheels only up to cp310.

## Package facts

- License: PSF (permissive)
- Python support: unspecified
- Install friction: medium
- Maintenance: active
- Downloads: 93.8K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

boolean array library, bit manipulation in python, efficient bitarray implementation, bitwise operations library, memory-efficient boolean storage, bit-manipulation, c-extension, memory-efficient

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